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Sample records for d-xylose breath test

  1. Predisposing factors for positive D-Xylose breath test for evaluation of small intestinal bacterial overgrowth: A retrospective study of 932 patients

    PubMed Central

    Schatz, Richard A; Zhang, Qing; Lodhia, Nilesh; Shuster, Jonathan; Toskes, Phillip P; Moshiree, Baharak

    2015-01-01

    AIM: To investigate, in the largest cohort to date, patient characteristics and associated risk factors for developing small intestinal bacterial overgrowth (SIBO) using the D-Xylose breath test (XBT). METHODS: We performed a retrospective cross-sectional study to analyze patient characteristics who underwent the XBT for evaluation of SIBO. Diagnostic testing with the XBT was performed based on a clinical suspicion for SIBO in patients with symptoms of bloating, abdominal pain, abdominal distension, weight loss, diarrhea, and/or constipation. Consecutive electronic medical records of 932 patients who completed the XBT at the University of Florida between 2005 and 2009 were reviewed. A two-way Analysis of Variance (ANOVA) was used to test for several associations including age, gender, and body mass index (BMI) with a +XBT. A two-way ANOVA was also performed to control for the differences and interaction with age and between genders. A similar analysis was repeated for BMI. Associations between medical conditions and prior surgical histories were conducted using the Mantel-Haenszel method for 2 by 2 contingency tables, stratified for gender. Reported odds ratio estimates reflect the odds of the prevalence of a condition within the +XBT group to that of the -XBT group. P values of less than 0.05 (two-sided) were considered statistically significant. RESULTS: In the 932 consecutive eligible subjects studied, 513 had a positive XBT. A positive association was found between female gender and a positive XBT (P = 0.0025), and females with a positive test were, on average, greater than 5 years older than those with a negative test (P = 0.024). The mean BMI of positive XBT subjects was normal (24.5) and significantly lower than the subjects with a negative XBT (29.5) (P = 0.0050). A positive XBT was associated with gastroesophageal reflux disease (GERD) (OR = 1.35; 95%CI: 1.02-1.80, P = 0.04), peptic ulcer disease (PUD) (OR = 2.61; 95%CI: 1.48-4.59, P < 0.01), gastroparesis

  2. The serum D-xylose test as a useful tool to identify malabsorption in rats with antigen specific gut inflammatory reaction.

    PubMed

    Antunes, Danielle Mota Fontes; da Costa, Janilda Pacheco; Campos, Sylvia Maria Nicolau; Paschoal, Patrícia Olaya; Garrido, Valéria; Siqueira, Munique; Teixeira, Gerlinde Agate Platais Brasil; Cardoso, Gilberto Perez

    2009-04-01

    The inappropriate immune response to foods, such as peanut, wheat and milk may be the basis in the pathogenesis of enteropathies like coeliac and Crohn disease, which present small intestinal malabsorption. A number of recent studies have utilized d-xylose absorption as an investigative tool to study small intestinal function in a variety of clinical settings. Thus, the aim of this experimental study was to evaluate the intestinal absorption of D-xylose in an antigen-specific gut inflammatory reaction rat model. Animals of the experimental group were inoculated with peanut protein extract before their exposure to a challenge diet containing exclusively peanut seeds to induce the gut inflammatory reaction caused by peanut allergy. Our results show that systemic inoculation with peanut protein extract renders significantly higher antibody titres (5.085 +/- 0.126 units) (P < 0.0001) than control rats (0.905 +/- 0.053 units) and that the antibody titres correlate positively to an inflammatory alteration of the gut morphology (P < 0.0001). Animals pertaining to the experimental group showed an intestinal absorption of D-xylose lower than control rats (P < 0.0001). We also observed that D-xylose absorption correlates negatively with IgG titres and positively with morphometric parameters (Pearson correlation). In conclusion, the use of serum D-xylose test was useful to identify the presence of small intestinal malabsorption in our antigen specific gut inflammatory reaction rat model.

  3. Experiments testing the abatement of radiation damage in D-xylose isomerase crystals with cryogenic helium.

    PubMed

    Hanson, B Leif; Harp, Joel M; Kirschbaum, Kristin; Schall, Constance A; DeWitt, Ken; Howard, Andrew; Pinkerton, A Alan; Bunick, Gerard J

    2002-11-01

    Helium is a more efficient cryogen than nitrogen, and for macromolecular data collection at high-flux beamlines will deliver lower temperatures. An open-flow helium cryostat developed at the University of Toledo (the Pinkerton Device) has been used for macromolecular data collection. This device differs from standard commercial He cryostats by having a much narrower aperture providing a high velocity stream of He around the crystal that maximizes convective and conductive heat exchange between the crystal and the cryogen. This paper details a series of experiments conducted at the IMCA-CAT 17ID beamline using one crystal for each experimental condition to examine whether helium at 16 K provided better radiation-damage abatement compared with nitrogen at 100 K. These studies used matched high-quality crystals (0.94 A diffraction resolution) of D-xylose isomerase derived from the commercial material Gensweet SGI. Comparisons show that helium indeed abates the indicators of radiation damage, in this case resulting in longer crystal diffractive lifetimes. The overall trend suggests that crystals maintain order and that high-resolution data are less affected by increased radiation load when crystals are cooled with He rather than N(2). This is probably the result of a lower effective temperature at the crystal with concomitant reduction in free-radical diffusion. Other features, such as an apparent phase transition in macromolecular crystals at lower temperatures, require investigation to broaden the utility of He use.

  4. The effect of canola meal tannins on the intestinal absorption capacity of broilers using a D-xylose test.

    PubMed

    Mansoori, B; Rogiewicz, A; Slominski, B A

    2015-12-01

    In three D-xylose absorption experiments, the effect of 1% HCl/methanol, 70% methanol or 70% acetone extracts of canola meal (CM) or 70% acetone extract of soybean meal (SBM) containing polyphenols, phenolic acids, tannins and phytic acid on intestinal absorption capacity of broilers was determined. In Exp. 1, the experimental groups received orally D-xylose solution alone or with methanol/HCl, methanol or acetone extracts of CM. In Exp. 2, the experimental groups received D-xylose alone or with acetone extracts of CM or SBM. In Exp. 3, the experimental groups received D-xylose plus sucrose solution or D-xylose plus acetone extracts of CM or SBM. In Exps. 2 and 3, the CM extracts contained 2.7 and 2.6, 2.4 and 2.3, 3.2 and 3.2, and 2.4 and 2.2 times higher polyphenols, phenolic acids, tannins and condensed tannins than the corresponding SBM extracts respectively. Blood samples were collected in 40-min intervals, and plasma D-xylose was measured. Compared to the Control, plasma D-xylose in Exp. 1 was lower (p < 0.001) by 81, 69 and 73% at 40-min, by 41, 44 and 37% at 80-min and by 22, 31, and 23% at 120-min post-ingestion of the HCl/methanol, methanol and acetone extracts respectively. In both Exps. 2 and 3, plasma D-xylose level was lower (p < 0.001) in groups dosed with CM extract or SBM extract at each time of blood collection, when compared to the respective Control group. However, in Exp. 3, birds dosed with SBM extract had higher plasma D-xylose than CM extract-dosed birds by 28, 8 and 21% at 40, 80 and 120 min respectively (p < 0.01). In conclusion, although CM extract caused a lower absorption of D-xylose, based on 5 to 10% of CM inclusion levels in practical broiler rations, the soluble bioactive components of CM will likely have minor impact on the absorption capacity of the chicken intestine.

  5. Breath alcohol test

    MedlinePlus

    Alcohol test - breath ... There are various brands of breath alcohol tests. Each one uses a different method to test the level of alcohol in the breath. The machine may be electronic or manual. One ...

  6. D-xylose absorption

    MedlinePlus

    Xylose tolerance test; Diarrhea - xylose; Malnutrition - xylose; Sprue - xylose; Celiac - xylose ... test if you have: Persistent diarrhea Signs of malnutrition Unexplained weight loss This test is primarily used ...

  7. Isolation and Screening of Yeasts That Ferment d-Xylose Directly to Ethanol

    PubMed Central

    Nigam, J. N.; Ireland, R. S.; Margaritis, A.; Lachance, M. A.

    1985-01-01

    Natural habitats of yeasts were examined for the presence of strains able to produce ethanol from d-xylose. Black knots, insect frass, and tree exudates were screened by enrichment in liquid d-xylose-yeast extract medium. These and each d-xylose-assimilating yeast in a collection from cactus fruits and Drosophila spp. were tested for alcohol production from this sugar. Among the 412 isolates examined, 36 produced more than 1 g of ethanol liter−1 from 20 g of d-xylose liter−1, all under aerated conditions. Closer examination of the strains indicated that their time courses of d-xylose fermentation followed different patterns. Some strains produced more biomass than ethanol, and among these, ethanol may or may not be assimilated rapidly after depletion of d-xylose. Others produced more ethanol than biomass, but all catabolized ethanol after carbohydrate exhaustion. Ethanol production appeared best at low pH values and under mild aeration. Possible correlations between the nutritional profiles of the yeasts and their ability to produce ethanol from d-xylose were explored by multivariate analysis. d-Xylose appeared slightly better utilized by yeasts which rate poorly in terms of fermentation. The fermentation of d-glucose had no bearing on d-xylose fermentation. No specific nutritional trait could discriminate well between better d-xylose fermentors and other yeasts. PMID:16346947

  8. Production of ethanol from D-xylose by using D-xylose isomerase and yeasts

    SciTech Connect

    Gong, C.S.; Chem, L.F.; Flickinger, M.C.; Chiang, L.C.; Tsao, G.T.

    1981-02-01

    D-xylulose, an intermediate of D-xylose catabolism, was observed to be fermentable to ethanol and carbon dioxide in a yield of greater than 80% by yeasts (including industrial bakers' yeast) under fermentative conditions. This conversion appears to be carried out by many yeasts known for D-glucose fermentation. In some yeasts, xylitol, in addition to ethanol, was produced from D-xylulose. Fermenting yeasts are also able to produce ethanol from D-xylose when D-xylose isomerizing enzyme is present. The results indicate that ethanol could be produced from D-xylose in a yield of greater than 80% by a two-step process. First. D-xylose is converted to D-xylulose by xylose isomerase. D-xylulose is then fermented to ethanol by yeasts.

  9. Alcoholic Fermentation of d-Xylose by Yeasts

    PubMed Central

    Toivola, Ansa; Yarrow, David; van den Bosch, Eduard; van Dijken, Johannes P.; Scheffers, W. Alexander

    1984-01-01

    Type strains of 200 species of yeasts able to ferment glucose and grow on xylose were screened for fermentation of d-xylose. In most of the strains tested, ethanol production was negligible. Nineteen were found to produce between 0.1 and 1.0 g of ethanol per liter. Strains of the following species produce more than 1 g of ethanol per liter in the fermentation test with 2% xylose: Brettanomyces naardenensis, Candida shehatae, Candida tenuis, Pachysolen tannophilus, Pichia segobiensis, and Pichia stipitis. Subsequent screening of these yeasts for their capacity to ferment d-cellobiose revealed that only Candida tenuis CBS 4435 was a good fermenter of both xylose and cellobiose under the test conditions used. PMID:16346558

  10. Breath Tests to Assess Alcoholic Liver Disease.

    PubMed

    Furnari, Manuele; Ahmed, Iftikhar; Erpecum, Karel J van; Savarino, Vincenzo; Giannini, Edoardo G

    2016-01-01

    The prevalence of Alcohol related Liver Disease (ALD) continues to rise all over the world due to changing drinking behaviour of the population. Liver disease due to excessive alcohol consumption causes significant morbidity and mortality, and poses a substantial economic burden to the health care resources. Early diagnosis and treatment of ALD may help prevent progression to cirrhosis and hepatocellular carcinoma. The last decade has seen a rising interest in potential use of non-invasive tests in clinical practice, including diagnosis and monitoring of chronic liver diseases. Over the past few decades, breath testing has been investigated extensively in the diagnosis of ALD, and has shown promising results in predicting the early stages of ALD. A variety of breath tests have been utilised in this regard including the13Clabelled breath tests, aminopyrine breath test , galactose breath test , methacetin breath test, and keto-isocaproic acid breath test. These tests have demonstrated good results in identification of both significant and severe liver disease among patients with ALD. Volatile Organic Compounds (VOC) are chemicals, which can be quantified in breath and other biological fluids, and represent physio-pathological activities within an individual. Alteration in the pattern of breath VOCs can be correlated with a number of diseases including ALD. Early stages of ALD can be detected using these breath tests, which can lead to adoption of preventive measures to reduce the progression of liver disease. This review focuses on the clinical utility of current and future breath tests, including breath VOC, as a non-invasive means of predicting early stages of ALD. PMID:27515960

  11. Hydrogen breath tests in gastrointestinal diseases.

    PubMed

    Rana, Satya Vati; Malik, Aastha

    2014-10-01

    Hydrogen breath tests are widely used to explore pathophysiology of functional gastrointestinal (GI) disorders. Small intestinal bacterial overgrowth (SIBO) and carbohydrate malabsorption are disorders detected by these tests that have been proposed to be of great importance for symptoms of GI diseases. Glucose hydrogen breath test is more acceptable for diagnosis of SIBO whereas lactose and fructose hydrogen breath tests are used for detection of lactose and fructose maldigestion respectively. Lactulose hydrogen breath test is also used widely to measure the orocecal transit time for GI motility. These methods are noninvasive and inexpensive. Many patients with functional gut disorders are unaware of the relationship between diet and GI symptoms they present. In particular, patients with chronic symptoms may regard their condition as normal and may not be aware that their symptoms can be effectively managed following a proper diagnosis. Patients with symptoms of abdominal pain, bloating, flatulence and altered bowel movements (diarrhea and constipation), or with a medical diagnosis of irritable bowel syndrome or celiac disease, may have undiagnosed carbohydrate malabsorption or SIBO. Hydrogen breath tests are specific and sensitive diagnostic tests that can be used to either confirm or eliminate the possibility of carbohydrate malabsorption or SIBO in such patients. Breath tests, though valuable tools, are underutilized in evaluating dyspepsia and functional bloating and diarrhea as well as suspected malabsorption. However, because of their simplicity, reproducibility and safety of procedure they are now being substituted to more uncomfortable and expensive techniques that were traditionally used in gastroenterology. PMID:25298621

  12. Breath Testing for Small Intestinal Bacterial Overgrowth: Should We Bother?

    PubMed

    Pimentel, Mark

    2016-03-01

    The hydrogen breath test is based on following breath hydrogen levels after the administration of a carbohydrate (most commonly lactulose) to a patient with suspected small intestinal bacterial overgrowth. The test is based on the interaction between the administered carbohydrate and the intestinal bacteria. The resulting fermentation produces hydrogen. A positive breath test is based on a breath hydrogen rise prior to the expected arrival time in the highly microbial cecum. Despite renewed enthusiasm for breath testing in recent years due to associations with conditions such as irritable bowel syndrome, breath testing poses many challenges. In this argument against breath testing, several pitfalls that complicate breath testing will be described. PMID:26902227

  13. Alcohol breath test: gas exchange issues.

    PubMed

    Hlastala, Michael P; Anderson, Joseph C

    2016-08-01

    The alcohol breath test is reviewed with a focus on gas exchange factors affecting its accuracy. The basis of the alcohol breath test is the assumption that alveolar air reaches the mouth during exhalation with no change in alcohol concentration. Recent investigations have shown that alcohol concentration is altered during its transit to the mouth. The exhaled alcohol concentration is modified by interaction with the mucosa of the pulmonary airways. Exhaled alcohol concentration is not an accurate indicator of alveolar alcohol concentration. Measuring alcohol concentration in the breath is very different process than measuring a blood level from air equilibrated with a blood sample. Airway exchange of alcohol leads to a bias against certain individuals depending on the anatomic and physiologic characteristics. Methodological modifications are proposed to improve the accuracy of the alcohol breath test to become fair to all. PMID:27197859

  14. Properties of D-Xylose Isomerase from Streptomyces albus

    PubMed Central

    Sanchez, Sergio; Smiley, Karl L.

    1975-01-01

    A partially purified D-xylose isomerase has been isolated from cells of Streptomyces albus NRRL 5778 and some of its properties have been determined. D-Glucose, D-xylose, D-ribose, L-arabinose, and L-rhamnose served as substrates for the enzyme with respective Km values of 86, 93, 350, 153, and 312 mM and Vmax values measuring 1.23, 2.9, 2.63, 0.153, and 0.048 μmol/min per mg of protein. The hexose D-allose was also isomerized. The enzyme was strongly activated by 1.0 mM Mg2+ but only partially activated by 1.0 mM Co2+. The respective Km values for Mg2+ and Co2+ were 0.3 and 0.003 mM. Mg2+ and Co2+ appear to have separate binding sites on the isomerase. These cations also protect the enzyme from thermal denaturation and from D-sorbitol inhibition. The optimum temperature for ketose formation was 70 to 80 C at pH values ranging from 7 to 9. D-Sorbitol acts as a competitive inhibitor with a Ki of 5.5 mM against D-glucose, D-xylose, and D-ribose. Induction experiments, Mg2+ activation, and D-sorbitol D-sorbitol inhibition indicated that a single enzyme (D-xylose isomerase) was responsible for the isomerization of the pentoses, methyl pentose, and glucose. PMID:239628

  15. Breathing air trailer acceptance test procedure

    SciTech Connect

    Kostelnik, A.J.

    1994-09-14

    This Acceptance Test Procedure (ATP) will document compliance with the requirements of WHC-S-0251 Rev. 0 and ECNs 613530 and 606113. The equipment being tested is a Breathing Air Supply Trailer purchased as a Design and Fabrication procurement activity for use in the core sampling program. The ATP was written by the Seller and will be performed by the Seller with representatives of the Westinghouse Hanford Company witnessing the test at the Seller`s location. This test procedure is to verify that the American Bristol Industries, Inc., Model 5014-0001 low pressure Mobile Breathing Air Trailer, meets or exceeds the requirements of the Westinghouse Hanford specification.

  16. Optoacoustic 13C-breath test analyzer

    NASA Astrophysics Data System (ADS)

    Harde, Hermann; Helmrich, Günther; Wolff, Marcus

    2010-02-01

    The composition and concentration of exhaled volatile gases reflects the physical ability of a patient. Therefore, a breath analysis allows to recognize an infectious disease in an organ or even to identify a tumor. One of the most prominent breath tests is the 13C-urea-breath test, applied to ascertain the presence of the bacterium helicobacter pylori in the stomach wall as an indication of a gastric ulcer. In this contribution we present a new optical analyzer that employs a compact and simple set-up based on photoacoustic spectroscopy. It consists of two identical photoacoustic cells containing two breath samples, one taken before and one after capturing an isotope-marked substrate, where the most common isotope 12C is replaced to a large extent by 13C. The analyzer measures simultaneously the relative CO2 isotopologue concentrations in both samples by exciting the molecules on specially selected absorption lines with a semiconductor laser operating at a wavelength of 2.744 μm. For a reliable diagnosis changes of the 13CO2 concentration of 1% in the exhaled breath have to be detected at a concentration level of this isotope in the breath of about 500 ppm.

  17. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Breath-alcohol test system. 862.3050 Section 862....3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in...

  18. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Breath-alcohol test system. 862.3050 Section 862....3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in...

  19. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Breath-alcohol test system. 862.3050 Section 862....3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in...

  20. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Breath-alcohol test system. 862.3050 Section 862....3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in...

  1. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breath-alcohol test system. 862.3050 Section 862....3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in...

  2. Comparison of Gavage, Water Bottle, and a High-Moisture Diet Bolus as Dosing Methods for Quantitative D-xylose Administration to B6D2F1 (Mus musculus) Mice

    NASA Technical Reports Server (NTRS)

    Zimmer, J. Paul; Lewis, Sherry M.; Moyer, Jerry L.

    1993-01-01

    Gavage, water bottle, and diet incorporation are 3 dosing methods used orally to administer test compounds to rodents. These 3 methods were compared in mice to determine which represented the most quantitative delivery system. For dietary incorporation, a high-moisture bolus form of NIH-31 rodent meal was developed using hydroxypropyl methylcellulose as an autoclave-stable binding agent. A high-moisture bolus were selected to increase the acceptability of the dosed diet and to promote quantitative consumption through reduced wastage. The test compound used was D-xylose, a pentose sugar that may be quantitatively detected, colorimetrically, in urine following oral dosing. Six male and 6 female B6D2FI mice were placed in metabolism cages and dosed with a known quantity of D-xylose by each of the 3 methods. Urine was collected before and after each method of administration and analysed for total D-xylose; the per cent recovery was based upon the amount of D-xylose consumed. Quantitative consumption was apparently greatest for water bottle dosing with an average recovery of 56.0% of the original D-xylose dose. High-moisture bolus incorporation ranked second with 50.0% D-xylose recovery, and gavage was third with 41.0% D-xylose recovery.

  3. Method for determining D-xylose in copper-plating solutions

    SciTech Connect

    Feemster, H.C.

    1981-04-01

    A modified colormetric procedure for the determination of low concentrations of D-xylose in copper sulfate-sulfuric acid plating baths is described. The D-xylose is added to the copper solutions to eliminate gas entrapment in the finished copper deposit. Determinations were made at 620 nm with concentrations between 0.01 to 0.1 mg D-xylose per ml. The system obeys Beer's Law at these concentrations.

  4. Production of xylitol from D-xylose by Debaryomyces hansenii

    SciTech Connect

    Dominguez, J.M.; Gong, Cheng S.; Tsao, G.T.

    1997-12-31

    Xylitol, a naturally occurring five-carbon sugar alcohol, can be produced from D-xylose through microbial hydrogenation. Xylitol has found increasing use in the food industries, especially in confectionary. It is the only so-called {open_quotes}second-generation polyol sweeteners{close_quotes} that is allowed to have the specific health claims in some world markets. In this study, the effect of cell density on the xylitol production by the yeast Debaryomyces hansenii NRRL Y-7426 from D-xylose under microaerobic conditions was examined. The rate of xylitol production increased with increasing yeast cell density to 3 g/L. Beyond this amount there was no increase in the xylitol production with increasing cell density. The optimal pH range for xylitol production was between 4.5 and 5.5. The optimal temperature was between 28 and 37{degrees}C, and the optimal shaking speed was 300 rpm. The rate of xylitol production increased linearly with increasing initial xylose concentration. A high concentration of xylose (279 g/L) was converted rapidly and efficiently to produce xylitol with a product concentration of 221 g/L was reached after 48 h of incubation under optimum conditions. 18 refs., 5 figs.

  5. Breath tests and irritable bowel syndrome.

    PubMed

    Rana, Satya Vati; Malik, Aastha

    2014-06-28

    Breath tests are non-invasive tests and can detect H₂ and CH₄ gases which are produced by bacterial fermentation of unabsorbed intestinal carbohydrate and are excreted in the breath. These tests are used in the diagnosis of carbohydrate malabsorption, small intestinal bacterial overgrowth, and for measuring the orocecal transit time. Malabsorption of carbohydrates is a key trigger of irritable bowel syndrome (IBS)-type symptoms such as diarrhea and/or constipation, bloating, excess flatulence, headaches and lack of energy. Abdominal bloating is a common nonspecific symptom which can negatively impact quality of life. It may reflect dietary imbalance, such as excess fiber intake, or may be a manifestation of IBS. However, bloating may also represent small intestinal bacterial overgrowth. Patients with persistent symptoms of abdominal bloating and distension despite dietary interventions should be referred for H₂ breath testing to determine the presence or absence of bacterial overgrowth. If bacterial overgrowth is identified, patients are typically treated with antibiotics. Evaluation of IBS generally includes testing of other disorders that cause similar symptoms. Carbohydrate malabsorption (lactose, fructose, sorbitol) can cause abdominal fullness, bloating, nausea, abdominal pain, flatulence, and diarrhea, which are similar to the symptoms of IBS. However, it is unclear if these digestive disorders contribute to or cause the symptoms of IBS. Research studies show that a proper diagnosis and effective dietary intervention significantly reduces the severity and frequency of gastrointestinal symptoms in IBS. Thus, diagnosis of malabsorption of these carbohydrates in IBS using a breath test is very important to guide the clinician in the proper treatment of IBS patients. PMID:24976698

  6. Breath tests and irritable bowel syndrome

    PubMed Central

    Rana, Satya Vati; Malik, Aastha

    2014-01-01

    Breath tests are non-invasive tests and can detect H2 and CH4 gases which are produced by bacterial fermentation of unabsorbed intestinal carbohydrate and are excreted in the breath. These tests are used in the diagnosis of carbohydrate malabsorption, small intestinal bacterial overgrowth, and for measuring the orocecal transit time. Malabsorption of carbohydrates is a key trigger of irritable bowel syndrome (IBS)-type symptoms such as diarrhea and/or constipation, bloating, excess flatulence, headaches and lack of energy. Abdominal bloating is a common nonspecific symptom which can negatively impact quality of life. It may reflect dietary imbalance, such as excess fiber intake, or may be a manifestation of IBS. However, bloating may also represent small intestinal bacterial overgrowth. Patients with persistent symptoms of abdominal bloating and distension despite dietary interventions should be referred for H2 breath testing to determine the presence or absence of bacterial overgrowth. If bacterial overgrowth is identified, patients are typically treated with antibiotics. Evaluation of IBS generally includes testing of other disorders that cause similar symptoms. Carbohydrate malabsorption (lactose, fructose, sorbitol) can cause abdominal fullness, bloating, nausea, abdominal pain, flatulence, and diarrhea, which are similar to the symptoms of IBS. However, it is unclear if these digestive disorders contribute to or cause the symptoms of IBS. Research studies show that a proper diagnosis and effective dietary intervention significantly reduces the severity and frequency of gastrointestinal symptoms in IBS. Thus, diagnosis of malabsorption of these carbohydrates in IBS using a breath test is very important to guide the clinician in the proper treatment of IBS patients. PMID:24976698

  7. Studies on the simultaneous enzymatic isomerization and yeast fermentation of D-xylose

    SciTech Connect

    Roman de Rodriguez Ganduglia, G.N.

    1983-01-01

    The addition of the enzyme D-xylose isomerase (glucose isomerase) to fermentation medium facilitates the conversion of D-xylose into ethanol by a two step process in which D-xylose is first isomerized to D-xylose, which is in turn converted to ethanol by yeast. Detailed kinetic studies were conducted independently for the isomerization reaction and for the fermentation of D-xylose by the yeast Schizosaccharomyces pombe. The kinetics of the isomerization reaction has been examined using a differential batch reactor at different temperatures and pH value. The kinetics of the utilization of D-xylose by the yeast Schizosaccharomyces pombe has been examined in presence of D-xylose and ethanol under anaerobic batch conditions. The effects of the concentration of each of the two sugars upon the production of ethanol were also examined. A combined model has been formulated that predicts the performance of the batch conversion of D-xylose to ethanol by the simultaneous isomerization/fermentation process. A reasonable agreement was found between experimental data and values calculated from the model.

  8. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation airflow will be measured in the facepiece or mouthpiece of open-circuit apparatus with air flowing at...

  9. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation airflow will be measured in the facepiece or mouthpiece of open-circuit apparatus with air flowing at...

  10. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation airflow will be measured in the facepiece or mouthpiece of open-circuit apparatus with air flowing at...

  11. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation airflow will be measured in the facepiece or mouthpiece of open-circuit apparatus with air flowing at...

  12. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air respirators shall employ one or two flexible breathing tubes of the nonkinking type which extend from...

  13. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air respirators shall employ one or two flexible breathing tubes of the nonkinking type which extend from...

  14. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air respirators shall employ one or two flexible breathing tubes of the nonkinking type which extend from...

  15. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air respirators shall employ one or two flexible breathing tubes of the nonkinking type which extend from...

  16. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air respirators shall employ one or two flexible breathing tubes of the nonkinking type which extend from...

  17. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation... machine as described in § 84.88. (b) The inhalation resistance of open-circuit apparatus shall not...

  18. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation... machine as described in § 84.88. (b) The inhalation resistance of open-circuit apparatus shall not...

  19. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation... machine as described in § 84.88. (b) The inhalation resistance of open-circuit apparatus shall not...

  20. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation... machine as described in § 84.88. (b) The inhalation resistance of open-circuit apparatus shall not...

  1. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation... machine as described in § 84.88. (b) The inhalation resistance of open-circuit apparatus shall not...

  2. Genetic and biochemical characterization of mutations affecting the ability of the yeast Pachysolen tannophilus to metabolize D-xylose

    SciTech Connect

    James, A.P.; Zahab, D.M.; Mahmourides, G.; Maleszka, R.; Schneider, H. )

    1989-11-01

    Induced mutants, selected for their defective growth on D-xylose while retaining the ability to grow normally on D-glucose, were studied in Pachysolen tannophilus, a yeast capable of converting D-xylose to ethanol. Fourteen of the mutations were found to occur at nine distinct loci, and data indicated that many more loci remain to be detected. Most of the mutations were pleiotropic in character, and the expression of some of them was much affected by nutritional conditions and by genetic background. Mutations at several loci resulted in poor growth on at least one compound that was either an intermediate of the tricarboxylic acid cycle, succinate or {alpha}-ketoglutarate, or on compounds metabolizable via this cycle, ethanol or glycerol. An initial biochemical characterization of the mutants was undertaken. Analysis for xylose reductase, xylitol dehydrogenase, and xylulose kinase activity showed that one or more of these activities was affected in 12 of 13 mutants. However, drastic reduction in activity of a single enzyme was confined to that of xylitol dehydrogenase by mutations at three different loci and to that of D-xylose reductase by mutation at another locus. Growth of these latter four mutants was normal on all carbon sources tested that were not five-carbon sugars.

  3. Breath testing for small intestinal bacterial overgrowth: maximizing test accuracy.

    PubMed

    Saad, Richard J; Chey, William D

    2014-12-01

    The diagnosis of small intestinal bacterial overgrowth (SIBO) has increased considerably owing to a growing recognition of its association with common bowel symptoms including chronic diarrhea, bloating, abdominal distention, and the irritable bowel syndrome. Ideally, an accurate and objective diagnosis of SIBO should be established before initiating antibiotic treatment. Unfortunately, no perfect test exists for the diagnosis of SIBO. The current gold standard, small-bowel aspiration and quantitative culture, is limited by its high cost, invasive nature, lack of standardization, sampling error, and need for dedicated infrastructure. Although not without shortcomings, hydrogen breath testing provides the simplest noninvasive and widely available diagnostic modality for suspected SIBO. Carbohydrates such as lactulose and glucose are the most widely used substrates in hydrogen breath testing, with glucose arguably providing greater testing accuracy. Lactose, fructose, and sorbitol should not be used as substrates in the assessment of suspected SIBO. The measurement of methane in addition to hydrogen can increase the sensitivity of breath testing for SIBO. Diagnostic accuracy of hydrogen breath testing in SIBO can be maximized by careful patient selection for testing, proper test preparation, and standardization of test performance as well as test interpretation.

  4. Breath testing for small intestinal bacterial overgrowth: maximizing test accuracy.

    PubMed

    Saad, Richard J; Chey, William D

    2014-12-01

    The diagnosis of small intestinal bacterial overgrowth (SIBO) has increased considerably owing to a growing recognition of its association with common bowel symptoms including chronic diarrhea, bloating, abdominal distention, and the irritable bowel syndrome. Ideally, an accurate and objective diagnosis of SIBO should be established before initiating antibiotic treatment. Unfortunately, no perfect test exists for the diagnosis of SIBO. The current gold standard, small-bowel aspiration and quantitative culture, is limited by its high cost, invasive nature, lack of standardization, sampling error, and need for dedicated infrastructure. Although not without shortcomings, hydrogen breath testing provides the simplest noninvasive and widely available diagnostic modality for suspected SIBO. Carbohydrates such as lactulose and glucose are the most widely used substrates in hydrogen breath testing, with glucose arguably providing greater testing accuracy. Lactose, fructose, and sorbitol should not be used as substrates in the assessment of suspected SIBO. The measurement of methane in addition to hydrogen can increase the sensitivity of breath testing for SIBO. Diagnostic accuracy of hydrogen breath testing in SIBO can be maximized by careful patient selection for testing, proper test preparation, and standardization of test performance as well as test interpretation. PMID:24095975

  5. D-Xylose as a sugar complement regulates blood glucose levels by suppressing phosphoenolpyruvate carboxylase (PEPCK) in streptozotocin-nicotinamide-induced diabetic rats and by enhancing glucose uptake in vitro

    PubMed Central

    Kim, Eunju; Kim, Yoo-Sun; Kim, Kyung-Mi; Jung, Sangwon; Yoo, Sang-Ho

    2016-01-01

    BACKGROUND/OBJECTIVES Type 2 diabetes (T2D) is more frequently diagnosed and is characterized by hyperglycemia and insulin resistance. D-Xylose, a sucrase inhibitor, may be useful as a functional sugar complement to inhibit increases in blood glucose levels. The objective of this study was to investigate the anti-diabetic effects of D-xylose both in vitro and stretpozotocin (STZ)-nicotinamide (NA)-induced models in vivo. MATERIALS/METHODS Wistar rats were divided into the following groups: (i) normal control; (ii) diabetic control; (iii) diabetic rats supplemented with a diet where 5% of the total sucrose content in the diet was replaced with D-xylose; and (iv) diabetic rats supplemented with a diet where 10% of the total sucrose content in the diet was replaced with D-xylose. These groups were maintained for two weeks. The effects of D-xylose on blood glucose levels were examined using oral glucose tolerance test, insulin secretion assays, histology of liver and pancreas tissues, and analysis of phosphoenolpyruvate carboxylase (PEPCK) expression in liver tissues of a STZ-NA-induced experimental rat model. Levels of glucose uptake and insulin secretion by differentiated C2C12 muscle cells and INS-1 pancreatic β-cells were analyzed. RESULTS In vivo, D-xylose supplementation significantly reduced fasting serum glucose levels (P < 0.05), it slightly reduced the area under the glucose curve, and increased insulin levels compared to the diabetic controls. D-Xylose supplementation enhanced the regeneration of pancreas tissue and improved the arrangement of hepatocytes compared to the diabetic controls. Lower levels of PEPCK were detected in the liver tissues of D-xylose-supplemented rats (P < 0.05). In vitro, both 2-NBDG uptake by C2C12 cells and insulin secretion by INS-1 cells were increased with D-xylose supplementation in a dose-dependent manner compared to treatment with glucose alone. CONCLUSIONS In this study, D-xylose exerted anti-diabetic effects in vivo by

  6. Aerobic Fermentation of D-Xylose to Ethanol by Clavispora sp

    PubMed Central

    Nigam, J. N.; Margaritis, A.; Lachance, M. A.

    1985-01-01

    Eleven strains of an undescribed species of Clavispora fermented D-xylose directly to ethanol under aerobic conditions. Strain UWO(PS)83-877-1 was grown in a medium containing 2% D-xylose and 0.5% yeast extract, and the following results were obtained: ethanol yield coefficient (ethanol/D-xylose), 0.29 g g−1 (57.4% of theoretical); cell yield coefficient (dry biomass/D-xylose), 0.25 g g−1; maximum ethanol concentration, 5.9 g liter−1; maximum volumetric ethanol productivity, 0.11 g liter−1 h−1. With initial D-xylose concentrations of 40, 60, and 80 g liter−1, maximum ethanol concentrations of 8.8, 10.9, and 9.8 g liter−1 were obtained, respectively (57.2, 57.1, and 48.3% of theoretical). Ethanol was found to inhibit the fermentation of D-xylose (Kp = 0.58 g liter−1) more than the fermentation of glucose (Kp = 6.5 g liter−1). The performance of this yeast compared favorably with that reported for some other D-xylose-fermenting yeasts. PMID:16346910

  7. Effect of inhibitors on D-xylose permeability in rat diaphragm muscle.

    PubMed

    POLLERI, A; MENOZZI, P; NORMAN, D; HECHTER, O

    1961-01-01

    The influence of metabolic inhibitors and low temperatures upon D-xylose transfer has been studied in rat diaphragm muscle preparations in vitro. Using intact fiber preparations, it has been confirmed that at body temperature metabolic inhibitors like DNP have an insulin-like action in that they permit D-xylose to distribute into previously unavailable intracellular aqueous regions; inhibitors, unlike insulin, disturb cation distribution in association with increased sugar penetration. Although the studies with inhibitors suggest an energy requirement for maintenance of D-xylose exclusion, the D-xylose exclusion mechanism is effectively maintained at 0 degrees for many hours, and under these conditions, inhibitors have little or no effect on D-xylose distribution, though they do produce potassium loss. In cut muscle fiber preparations, in which insulin significantly increases the rate at which D-xylose equilibrates between cell water and external medium, DNP does not increase the rate of D-xylose entry, but does abolish the effect of insulin in this preparation. The results suggest that insulin action upon sugar permeability in muscle involves two barrier systems; some of the characteristics of these systems have been defined.

  8. Continuous fermentation of D-xylose by immobilized Pichia stipitis

    SciTech Connect

    Nunez, M.J.; Dominguez, C.H.; Sanroman, A.; Lema, J.M.

    1991-12-31

    The main purpose of this work was to compare the performance of two different kinds of reactors (CSTR and CPFR) in order to enhance the ethanol productivity in the fermentation of D-xylose by Pichia steps immobilized in {kappa}-carrageenan. Immobilization was carried out in a 4% aqueous suspension of {kappa}-carrageenan, which was mixed with the inoculum. The bioparticles were treated with Al(NO{sub 3}){sub 3} as hardening agent. The fermenters operated during a long period of time (about 30 d). Best results were obtained in the packed-bed reactor (CPFR), which allowed operation at high final ethanol concentrations, this fact having been explained because of the observed strong product inhibition. The overall productivity reached values higher than 3.8 g/(L{circ}h). This supposed an interesting improvement with relation to the productivities found in the literature, which as an average did not exceed 1 g/(L{circ}h). However, the specific productivities of yeast in the continuous stirred tank reactor (CSTR) were always greater because the bioparticles were kept in close contact with the broth, whereas in the CPFR, there were at least two problems: (a) the possibility that the produced gas could prevent the intimate contact between the substrate and the particles and (b) the possible existence of preferential paths.

  9. Monitoring breath during oral glucose tolerance tests.

    PubMed

    Ghimenti, S; Tabucchi, S; Lomonaco, T; Di Francesco, F; Fuoco, R; Onor, M; Lenzi, S; Trivella, M G

    2013-03-01

    The evolution of breath composition during oral glucose tolerance tests (OGTTs) was analysed by thermal desorption/gas chromatography/mass spectrometry in 16 subjects and correlated to blood glucose levels. The glucose tolerance tests classified five of the subjects as diabetics, eight as affected by impaired glucose tolerance and three as normoglycaemic. Acetone levels were generally higher in diabetics (average concentration values: diabetics, 300 ± 40 ppbv; impaired glucose tolerance, 350 ± 30 ppbv; normoglycaemic, 230 ± 20 ppbv) but the large inter-individual variability did not allow us to identify the three groups by this parameter alone. The exhalation of 3-hydroxy-butan-2-one and butane-2,3-dione, likely due to the metabolization of glucose by bacteria in the mouth, was also observed. Future work will involve the extension of the analyses to other volatile compounds by attempting to improve the level of discrimination between the various classes of subjects. PMID:23446273

  10. Development of a new method for d-xylose detection and quantification in urine, based on the use of recombinant xylose dehydrogenase from Caulobacter crescentus.

    PubMed

    Sánchez-Moreno, Israel; García-Junceda, Eduardo; Hermida, Carmen; Fernández-Mayoralas, Alfonso

    2016-09-20

    The gene xylB from Caulobacter crescentus has been cloned and expressed in Escherichia coli providing a high yield of xylose dehydrogenase (XylB) production and excellent purity (97%). Purified recombinant XylB showed an absolute dependence on the cofactor NAD(+) and a strong preference for d-xylose against other assayed mono and disaccharides. Additionally, XylB showed strong stability when stored as freeze-dried powder at least 250days both at 4°C and room temperature. In addition, more than 80% of the initial activity of rehydrated freeze-dried enzyme remained after 150days of incubation at 4°C. Based on these characteristics, the capability of XylB in d-xylose detection and quantification was studied. The linearity of the method was maintained up to concentrations of d-xylose of 10mg/dL and the calculated limits of detection (LoD) and quantification (LoQ) of xylose in buffer were 0.568mg/dL and 1.89mg/dL respectively. Thus, enzymatic detection was found to be an excellent method for quantification of d-xylose in both buffer and urine samples. This method can easily be incorporated in a new test for the diagnosis of hypolactasia through the measurement of intestinal lactase activity. PMID:27480343

  11. Concurrent production and consumption of ethanol by cultures of Pachysolen tannophilus growing on d-xylose

    SciTech Connect

    Maleszka, R.; Schneider, H.

    1982-01-01

    Growing cultures of P. tannaphilus concurrently consumed and produced ethanol in the presence of substantial concentrations of D-xylose. Ethanol was also assimilated in the presence of other sugars, the amount depending on the sugar. Less ethanol assimilation occurred with D-glucose than with D-xylose. The rate of ethanol consumption decreased as the concentration of glucose was increased, but some consumption still occurred when 2% glucose was present. The rate increased with the amount of O2 available to the culture when D-xylose or ethanol was the C source. The results are pertinent to the use of P. tannophilus for the production of ethanol from D-xylose.

  12. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be... each test conducted in accordance with §§ 84.124, 84.125, and 84.126, with air flowing at a...

  13. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing resistance test; minimum requirements. 84... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance to... mounted on a test fixture with air flowing at a continuous rate of 85 liters per minute, both before...

  14. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing resistance test; minimum requirements. 84... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance to... mounted on a test fixture with air flowing at a continuous rate of 85 liters per minute, both before...

  15. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing resistance test; minimum requirements. 84... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance to... mounted on a test fixture with air flowing at a continuous rate of 85 liters per minute, both before...

  16. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing resistance test; minimum requirements. 84... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance to... mounted on a test fixture with air flowing at a continuous rate of 85 liters per minute, both before...

  17. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be... each test conducted in accordance with §§ 84.124, 84.125, and 84.126, with air flowing at a...

  18. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be... each test conducted in accordance with §§ 84.124, 84.125, and 84.126, with air flowing at a...

  19. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; minimum requirements. 84... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance to... mounted on a test fixture with air flowing at a continuous rate of 85 liters per minute, both before...

  20. 46 CFR 197.450 - Breathing gas tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Breathing gas tests. 197.450 Section 197.450 Shipping....450 Breathing gas tests. The diving supervisor shall insure that— (a) The output of each air..., supplying mixed-gas to a diver, is checked, prior to commencement of diving operations, at the umbilical...

  1. 46 CFR 197.450 - Breathing gas tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Breathing gas tests. 197.450 Section 197.450 Shipping....450 Breathing gas tests. The diving supervisor shall insure that— (a) The output of each air..., supplying mixed-gas to a diver, is checked, prior to commencement of diving operations, at the umbilical...

  2. Coconut-derived D-xylose affects postprandial glucose and insulin responses in healthy individuals

    PubMed Central

    Bae, Yun Jung; Bak, Youn-Kyung; Kim, Bumsik; Kim, Min-Sun; Lee, Jin-Hee

    2011-01-01

    Metabolic alterations including postprandial hyperglycemia have been implicated in the development of obesity-related diseases. Xylose is a sucrase inhibitor suggested to suppress the postprandial glucose surge. The objectives of this study were to assess the inhibitory effects of two different concentrations of xylose on postprandial glucose and insulin responses and to evaluate its efficacy in the presence of other macronutrients. Randomized double-blind cross-over studies were conducted to examine the effect of D-xylose on postprandial glucose and insulin response following the oral glucose tolerance test (OGTT). In study 1, the overnight-fasted study subjects (n = 49) consumed a test sucrose solution (50 g sucrose in 130 ml water) containing 0, 5, or 7.5 g D-xylose powder. In study 2, the overnight-fasted study subjects (n = 50) consumed a test meal (50 g sucrose in a 60 g muffin and 200 ml sucrose-containing solution). The control meal provided 64.5 g of carbohydrates, 4.5 g of fat, and 10 g of protein. The xylose meal was identical to the control meal except 5 g of xylose was added to the muffin mix. In study 1, the 5 g xylose-containing solutions exhibited significantly lower area under the glucose curve (AUCg) and area under the insulin curve (AUCi) values for 0-15 min (P < 0.0001, P < 0.0001), 0-30 min (P < 0.0001, P < 0.0001), 0-45 min (P < 0.0001, P < 0.0001), 0-60 min (P < 0.0001, P < 0.0001), 0-90 min (P < 0.0001, P < 0.0001) and 0-120 min (P = 0.0071, P = 0.0016). In study 2, the test meal exhibited significantly lower AUCg and AUCi values for 0-15 min (P < 0.0001, P < 0.0001), 0-30 min (P < 0.0001, P < 0.0001), 0-45 min (P < 0.0001, P = 0.0005), 0-60 min (P = 0.0002, P = 0.0025), and 0-90 min (P = 0.0396, P = 0.0246). In conclusion, xylose showed an acute suppressive effect on the postprandial glucose and insulin surges. PMID:22259678

  3. NADP(+)-dependent D-xylose dehydrogenase from pig liver. Purification and properties.

    PubMed

    Zepeda, S; Monasterio, O; Ureta, T

    1990-03-15

    An NADP(+)-dependent D-xylose dehydrogenase from pig liver cytosol was purified about 2000-fold to apparent homogeneity with a yield of 15% and specific activity of 6 units/mg of protein. An Mr value of 62,000 was obtained by gel filtration. PAGE in the presence of SDS gave an Mr value of 32,000, suggesting that the native enzyme is a dimer of similar or identical subunits. D-Xylose, D-ribose, L-arabinose, 2-deoxy-D-glucose, D-glucose and D-mannose were substrates in the presence of NADP+ but the specificity constant (ratio kcat./Km(app.)) is, by far, much higher for D-xylose than for the other sugars. The enzyme is specific for NADP+; NAD+ is not reduced in the presence of D-xylose or other sugars. Initial-velocity studies for the forward direction with xylose or NADP+ concentrations varied at fixed concentrations of the nucleotide or the sugar respectively revealed a pattern of parallel lines in double-reciprocal plots. Km values for D-xylose and NADP+ were 8.8 mM and 0.99 mM respectively. Dead-end inhibition studies to confirm a ping-pong mechanism showed that NAD+ acted as an uncompetitive inhibitor versus NADP+ (Ki 5.8 mM) and as a competitive inhibitor versus xylose. D-Lyxose was a competitive inhibitor versus xylose and uncompetitive versus NADP+. These results fit better to a sequential compulsory ordered mechanism with NADP+ as the first substrate, but a ping-pong mechanism with xylose as the first substrate has not been ruled out. The presence of D-xylose dehydrogenase suggests that in mammalian liver D-xylose is utilized by a pathway other than the pentose phosphate pathway.

  4. Physiological properties of a mutant of Pachysolen tannophilus deficient in NADPH-dependent D-xylose reductase

    SciTech Connect

    Schneider, H.; James, A.P. ); Lee, Hung; Barbosa, M. De F.S. Univ. of Guelph, Ontario ); Kubicek, C.P. )

    1989-11-01

    A D-xylose reductase mutant of Pachysolen tannophilus was isolated on the basis of its poor growth on D-xylose but normal growth on xylitol and D-glucose. Fractionation of cell extracts indicated that the mutant was deficient in D-cylose reductase activity that used NADPH exclusively as a cofactor, but not in activity that used both NADH and NADPH. Mutant cultures grown on D-xylose as the sole carbon source exhibited some properties that would be desired in improved strains. Growth rate, growth yield, and D-xylose consumption rate of the mutant were less sensitive than those of the wild type to changes in aeration rate. D-Xylose was utilized more efficiently in that less of a by-product, xylitol, was produced. In addition, under low aeration conditions, more ethanol was produced. A disadvantage was a relatively slow rate of D-xylose utilization.

  5. Breath tests in diagnosis of pulmonary tuberculosis.

    PubMed

    Cheepsattayakorn, Attapon; Cheepsattayakorn, Ruangrong

    2014-01-01

    Since the time of Hippocrates, physicians have known that the odour of human breath can provide clues to diagnosis. In the past, hydrogen peroxide which is a marker of inflammatory diseases and oxidative stress was the most studied substance in the exhaled breath which was detectable in the liquid that obtained by condensing or cooling. The advantages of breath analysis are that it is convenient, non-invasive, and could be performed with children as well as mechanically ventilated patients. Today, exhaled nitric oxide has been studied extensively, especially in relation to asthma. More than a thousand different volatile organic compounds have been observed in low concentrations in normal human breath. Alkanes and methylalkanes have been increasingly used by physicians as a novel method to diagnose many diseases without discomforts of invasive procedures. Although the limitations of measurement of exhaled nitric oxide in direct diagnosis of infectious pulmonary TB, it may have potential development as a cost-effective replacement of chest radiological examination in screening algorithms. None of the individual exhaled volatile organic compound alone is specific for disease. Exhaled breath analysis techniques may be available to diagnose and monitor the diseases in home setting when their sensitivity and specificity are expected to improve in the future. Here, we also discussed some patents related to the topic. PMID:25185981

  6. Breathing simulator of workers for respirator performance test

    PubMed Central

    YUASA, Hisashi; KUMITA, Mikio; HONDA, Takeshi; KIMURA, Kazushi; NOZAKI, Kosuke; EMI, Hitoshi; OTANI, Yoshio

    2014-01-01

    Breathing machines are widely used to evaluate respirator performance but they are capable of generating only limited air flow patterns, such as, sine, triangular and square waves. In order to evaluate the respirator performance in practical use, it is desirable to test the respirator using the actual breathing patterns of wearers. However, it has been a difficult task for a breathing machine to generate such complicated flow patterns, since the human respiratory volume changes depending on the human activities and workload. In this study, we have developed an electromechanical breathing simulator and a respiration sampling device to record and reproduce worker’s respiration. It is capable of generating various flow patterns by inputting breathing pattern signals recorded by a computer, as well as the fixed air flow patterns. The device is equipped with a self-control program to compensate the difference in inhalation and exhalation volume and the measurement errors on the breathing flow rate. The system was successfully applied to record the breathing patterns of workers engaging in welding and reproduced the breathing patterns. PMID:25382381

  7. A Systematic Approach to Multiple Breath Nitrogen Washout Test Quality

    PubMed Central

    Klingel, Michelle; Pizarro, Maria Ester; Hall, Graham L.; Ramsey, Kathryn; Foong, Rachel; Saunders, Clare; Robinson, Paul D.; Webster, Hailey; Hardaker, Kate; Kane, Mica; Ratjen, Felix

    2016-01-01

    Background Accurate estimates of multiple breath washout (MBW) outcomes require correct operation of the device, appropriate distraction of the subject to ensure they breathe in a manner representative of their relaxed tidal breathing pattern, and appropriate interpretation of the acquired data. Based on available recommendations for an acceptable MBW test, we aimed to develop a protocol to systematically evaluate MBW measurements based on these criteria. Methods 50 MBW test occasions were systematically reviewed for technical elements and whether the breathing pattern was representative of relaxed tidal breathing by an experienced MBW operator. The impact of qualitative and quantitative criteria on inter-observer agreement was assessed across eight MBW operators (n = 20 test occasions, compared using a Kappa statistic). Results Using qualitative criteria, 46/168 trials were rejected: 16.6% were technically unacceptable and 10.7% were excluded due to inappropriate breathing pattern. Reviewer agreement was good using qualitative criteria and further improved with quantitative criteria from (κ = 0.53–0.83%) to (κ 0.73–0.97%), but at the cost of exclusion of further test occasions in this retrospective data analysis. Conclusions The application of the systematic review improved inter-observer agreement but did not affect reported MBW outcomes. PMID:27304432

  8. Metabolic engineering of Saccharomyces cerevisiae for bioconversion of D-xylose to D-xylonate.

    PubMed

    Toivari, Mervi; Nygård, Yvonne; Kumpula, Esa-Pekka; Vehkomäki, Maija-Leena; Benčina, Mojca; Valkonen, Mari; Maaheimo, Hannu; Andberg, Martina; Koivula, Anu; Ruohonen, Laura; Penttilä, Merja; Wiebe, Marilyn G

    2012-07-01

    An NAD(+)-dependent D-xylose dehydrogenase, XylB, from Caulobacter crescentus was expressed in Saccharomyces cerevisiae, resulting in production of 17 ± 2 g D-xylonate l(-1) at 0.23 gl(-1)h(-1) from 23 g D-xylose l(-1) (with glucose and ethanol as co-substrates). D-Xylonate titre and production rate were increased and xylitol production decreased, compared to strains expressing genes encoding T. reesei or pig liver NADP(+)-dependent D-xylose dehydrogenases. D-Xylonate accumulated intracellularly to ∼70 mgg(-1); xylitol to ∼18 mgg(-1). The aldose reductase encoding gene GRE3 was deleted to reduce xylitol production. Cells expressing D-xylonolactone lactonase xylC from C. crescentus with xylB initially produced more extracellular D-xylonate than cells lacking xylC at both pH 5.5 and pH 3, and sustained higher production at pH 3. Cell vitality and viability decreased during D-xylonate production at pH 3.0. An industrial S. cerevisiae strain expressing xylB efficiently produced 43 g D-xylonate l(-1) from 49 g D-xylose l(-1).

  9. Overexpression of NADH-dependent fumarate reductase improves D-xylose fermentation in recombinant Saccharomyces cerevisiae.

    PubMed

    Salusjärvi, Laura; Kaunisto, Sanna; Holmström, Sami; Vehkomäki, Maija-Leena; Koivuranta, Kari; Pitkänen, Juha-Pekka; Ruohonen, Laura

    2013-12-01

    Deviation from optimal levels and ratios of redox cofactors NAD(H) and NADP(H) is common when microbes are metabolically engineered. The resulting redox imbalance often reduces the rate of substrate utilization as well as biomass and product formation. An example is the metabolism of D-xylose by recombinant Saccharomyces cerevisiae strains expressing xylose reductase and xylitol dehydrogenase encoding genes from Scheffersomyces stipitis. This pathway requires both NADPH and NAD(+). The effect of overexpressing the glycosomal NADH-dependent fumarate reductase (FRD) of Trypanosoma brucei in D-xylose-utilizing S. cerevisiae alone and together with an endogenous, cytosol directed NADH-kinase (POS5Δ17) was studied as one possible solution to overcome this imbalance. Expression of FRD and FRD + POS5Δ17 resulted in 60 and 23 % increase in ethanol yield, respectively, on D-xylose under anaerobic conditions. At the same time, xylitol yield decreased in the FRD strain suggesting an improvement in redox balance. We show that fumarate reductase of T. brucei can provide an important source of NAD(+) in yeast under anaerobic conditions, and can be useful for metabolic engineering strategies where the redox cofactors need to be balanced. The effects of FRD and NADH-kinase on aerobic and anaerobic D-xylose and D-glucose metabolism are discussed.

  10. Alcoholic fermentation of d-xylose by yeasts. [Brettanomyces naardenensis; Candida shehatae; Candida tenuis; Pachysolen tannaphilus, Pichia segobiensis; Pichia stipitis

    SciTech Connect

    Toivola, A.; Yarrow, D.; van den Bosch, E.; van Dijken, J.P.; Scheffers, W.A.

    1984-06-01

    Type strains of 200 species of yeasts able to ferment glucose and grow on xylose were screened for fermentation of D-xylose. In most of the strains tested, ethanol production was negligible. Nineteen were found to produce between 0.1 and 1.0 g of ethanol per liter. Strains of the following species produce more than 1 g of ethanol per liter in the fermentation test with 2% xylose: Brettanomyces naardenensis, Candida shehatae, Candida tenuis, Pachysolen tannophilus, Pichia segobiensis, and Pichia stipitis. Subsequent screening of these yeasts for their capacity to ferment D-cellobiose revealed that only Candida tenuis CBS 4435 was a good fermenter of both xylose and cellobiose under the test conditions used.

  11. New optical analyzer for 13C-breath test

    NASA Astrophysics Data System (ADS)

    Harde, Hermann; Dressler, Matthias; Helmrich, Günther; Wolff, Marcus; Groninga, Hinrich

    2008-04-01

    Medical breath tests are well established diagnostic tools, predominantly for gastroenterological inspections, but also for many other examinations. Since the composition and concentration of exhaled volatile gases reflect the physical condition of a patient, a breath analysis allows one to recognize an infectious disease in an organ or even to identify a tumor. One of the most prominent breath tests is the 13C-urea-breath test, applied to ascertain the presence of the bacterium helicobacter pylori in the stomach wall as an indication of a gastric ulcer. In this contribution we present a new optical analyzer that is based on photoacoustic spectroscopy and uses a DFB diode laser at 2.744 μm. The concentration ratio of the CO II isotopologues is determined by measuring the absorption on a 13CO II line in comparison to a 12CO II line. In the specially selected spectral range the lines have similar strengths, although the concentrations differ by a factor of 90. Therefore, the signals are well comparable. Due to an excellent signal-noise-ratio isotope variations of less than 1% can be resolved as required for the breath test.

  12. Modified occlusion tests for the Bain breathing system.

    PubMed

    Heath, P J; Marks, L F

    1991-03-01

    Undetected defects in the inner tube of the Bain coaxial anaesthetic breathing system may result in a greatly increased apparatus deadspace. Several authorities have advocated tests intended to detect inner tube problems; however, the efficacy of these tests has never been validated. In this study none of the tests were able to detect all the induced defects. A modification of an existing test using the backbar pressure-relief valve and a new double occlusion test were sufficiently sensitive to detect all defects.

  13. Diversity and Physiological Characterization of D-Xylose-Fermenting Yeasts Isolated from the Brazilian Amazonian Forest

    PubMed Central

    Cadete, Raquel M.; Melo, Monaliza A.; Dussán, Kelly J.; Rodrigues, Rita C. L. B.; Silva, Silvio S.; Zilli, Jerri E.; Vital, Marcos J. S.; Gomes, Fátima C. O.; Lachance, Marc-André; Rosa, Carlos A.

    2012-01-01

    Background This study is the first to investigate the Brazilian Amazonian Forest to identify new D-xylose-fermenting yeasts that might potentially be used in the production of ethanol from sugarcane bagasse hemicellulosic hydrolysates. Methodology/Principal Findings A total of 224 yeast strains were isolated from rotting wood samples collected in two Amazonian forest reserve sites. These samples were cultured in yeast nitrogen base (YNB)-D-xylose or YNB-xylan media. Candida tropicalis, Asterotremella humicola, Candida boidinii and Debaryomyces hansenii were the most frequently isolated yeasts. Among D-xylose-fermenting yeasts, six strains of Spathaspora passalidarum, two of Scheffersomyces stipitis, and representatives of five new species were identified. The new species included Candida amazonensis of the Scheffersomyces clade and Spathaspora sp. 1, Spathaspora sp. 2, Spathaspora sp. 3, and Candida sp. 1 of the Spathaspora clade. In fermentation assays using D-xylose (50 g/L) culture medium, S. passalidarum strains showed the highest ethanol yields (0.31 g/g to 0.37 g/g) and productivities (0.62 g/L·h to 0.75 g/L·h). Candida amazonensis exhibited a virtually complete D-xylose consumption and the highest xylitol yields (0.55 g/g to 0.59 g/g), with concentrations up to 25.2 g/L. The new Spathaspora species produced ethanol and/or xylitol in different concentrations as the main fermentation products. In sugarcane bagasse hemicellulosic fermentation assays, S. stipitis UFMG-XMD-15.2 generated the highest ethanol yield (0.34 g/g) and productivity (0.2 g/L·h), while the new species Spathaspora sp. 1 UFMG-XMD-16.2 and Spathaspora sp. 2 UFMG-XMD-23.2 were very good xylitol producers. Conclusions/Significance This study demonstrates the promise of using new D-xylose-fermenting yeast strains from the Brazilian Amazonian Forest for ethanol or xylitol production from sugarcane bagasse hemicellulosic hydrolysates. PMID:22912807

  14. Identification and characterization of D-xylose reductase involved in pentose catabolism of the zygomycetous fungus Rhizomucor pusillus.

    PubMed

    Komeda, Hidenobu; Yamasaki-Yashiki, Shino; Hoshino, Kazuhiro; Asano, Yasuhisa

    2015-01-01

    Rhizomucor pusillus NBRC 4578 efficiently produces ethanol from lignocellulosic biomass because of its ability to ferment not only d-glucose, but also d-xylose. When the strain was cultivated on d-xylose, ethanol was gradually formed in the culture medium with a decrease in d-xylose and the simultaneous accumulation of xylitol, which suggested that the strain catabolized d-xylose with d-xylose reductase (XR) and xylitol dehydrogenase (XDH). XR (RpXR) was purified to homogeneity from the crude extract prepared from the mycelia of the strain grown on d-xylose. The purified enzyme was found to be NADPH-dependent and prefer pentoses such as d-xylose, d-ribose, and l-arabinose as substrates. Isolation of the genomic DNA and cDNA of the xyl1 gene encoding RpXR revealed that the gene was interrupted by two introns and the exon of the gene encoded a protein composed of 322 amino acids with a Mr of 36,724. Phylogenetic analysis showed that RpXR is more related to 4-dihydromethyltrisporate dehydrogenases from Mucoraseae fungi rather than the previously reported fungal XRs. Quantitative real-time PCR indicated that transcription of the xyl1 gene was marked in the presence of d-xylose and l-arabinose, but was week in the presence of d-glucose. These biochemical and expression analyses suggest that RpXR is involved in the catabolism of l-arabinose as well as d-xylose. This is the first report of the purification, characterization, and gene cloning of XR from zygomycetous fungi.

  15. A Quasi-Laue Neutron Crystallographic Study of D-Xylose Isomerase

    NASA Technical Reports Server (NTRS)

    Meilleur, Flora; Snell, Edward H.; vanderWoerd, Mark; Judge, Russell A.; Myles, Dean A. A.

    2006-01-01

    Hydrogen atom location and hydrogen bonding interaction determination are often critical to explain enzymatic mechanism. Whilst it is difficult to determine the position of hydrogen atoms using X-ray crystallography even with subatomic (less than 1.0 Angstrom) resolution data available, neutron crystallography provides an experimental tool to directly localise hydrogeddeuteriwn atoms in biological macromolecules at resolution of 1.5-2.0 Angstroms. Linearisation and isomerisation of xylose at the active site of D-xylose isomerase rely upon a complex hydrogen transfer. Neutron quasi-Laue data were collected on Streptomyces rubiginosus D-xylose isomerase crystal using the LADI instrument at ILL with the objective to provide insight into the enzymatic mechanism (Myles et al. 1998). The neutron structure unambiguously reveals the protonation state of His 53 in the active site, identifying the model for the enzymatic pathway.

  16. 42 CFR 84.88 - Breathing bag test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing bag test. 84.88 Section 84.88 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained...

  17. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; minimum requirements. 84.122 Section 84.122 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES...

  18. 42 CFR 84.88 - Breathing bag test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing bag test. 84.88 Section 84.88 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained...

  19. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing resistance test; minimum requirements. 84.122 Section 84.122 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES...

  20. High yield production of D-xylonic acid from D-xylose using engineered Escherichia coli.

    PubMed

    Liu, Huaiwei; Valdehuesa, Kris Niño G; Nisola, Grace M; Ramos, Kristine Rose M; Chung, Wook-Jin

    2012-07-01

    An engineered Escherichia coli was constructed to produce D-xylonic acid, one of the top 30 high-value chemicals identified by US Department of Energy. The native pathway for D-xylose catabolism in E. coli W3110 was blocked by disrupting xylose isomerase (XI) and xylulose kinase (XK) genes. The native pathway for xylonic acid catabolism was also blocked by disrupting two genes both encoding xylonic acid dehydratase (yagE and yjhG). Through the introduction of a D-xylose dehydrogenase from Caulobacter crescentus, a D-xylonic acid producing E. coli was constructed. The recombinant E. coli produced up to 39.2 g L(-1) D-xylonic acid from 40 g L(-1) D-xylose in M9 minimal medium. The average productivity was as high as 1.09 g L(-1) h(-1) and no gluconic acid byproduct was produced. These results suggest that the engineered E. coli has a promising application for the industrial-scale production of D-xylonic acid.

  1. High yield production of D-xylonic acid from D-xylose using engineered Escherichia coli.

    PubMed

    Liu, Huaiwei; Valdehuesa, Kris Niño G; Nisola, Grace M; Ramos, Kristine Rose M; Chung, Wook-Jin

    2012-07-01

    An engineered Escherichia coli was constructed to produce D-xylonic acid, one of the top 30 high-value chemicals identified by US Department of Energy. The native pathway for D-xylose catabolism in E. coli W3110 was blocked by disrupting xylose isomerase (XI) and xylulose kinase (XK) genes. The native pathway for xylonic acid catabolism was also blocked by disrupting two genes both encoding xylonic acid dehydratase (yagE and yjhG). Through the introduction of a D-xylose dehydrogenase from Caulobacter crescentus, a D-xylonic acid producing E. coli was constructed. The recombinant E. coli produced up to 39.2 g L(-1) D-xylonic acid from 40 g L(-1) D-xylose in M9 minimal medium. The average productivity was as high as 1.09 g L(-1) h(-1) and no gluconic acid byproduct was produced. These results suggest that the engineered E. coli has a promising application for the industrial-scale production of D-xylonic acid. PMID:21917451

  2. Fermentation of D-xylose to ethanol by genetically modified Klebsiella planticola

    SciTech Connect

    Tolan, J.S.; Finn, R.K.

    1987-09-01

    D-Xylose is a plentiful pentose sugar derived from agricultural or forest residues. Enteric bacteria such as Klebsiella spp. ferment D-xylose to form mixed acids and butanediol in addition to ethanol. Thus, the ethanol yield is normally low. This report describes the fermentation of D-xylose by Klebsiella planticola ATCC 33531 bearing multicopy plasmids containing the pdc gene inserted from Zymomonas mobilis. Expression of the gene markedly increased the yield of ethanol to 1.3 mol/mol of xylose, or 25.1 g/liter. Concurrently, there were significant decreases in the yields of formate, acetate, lactate, and butanediol. Transconjugant Klebsiella spp. grew almost as fast as the wild type and tolerated up to 4% ethanol. The plasmid was retained by the cells during at least one batch culture, even in the absence of selective pressure by antibiotics to maintain the plasmid. Ethanol production was 31.6 g/liter from 79.6 g of mixed substrate per liter chosen to simulate hydrolyzed hemicellulose. The physiology of the wild-type of K. planticola is described in more detail than in the original report of its isolation.

  3. The measurand problem in infrared breath alcohol testing

    NASA Astrophysics Data System (ADS)

    Vosk, Ted

    2012-02-01

    Measurements are made to determine the value of a quantity known as a measurand. The measurand is not always the quantity subject to measurement, however. Often, a distinct quantity will be measured and related to the measurand through a measurement function. When the identities of the measurand and the quantity actually measured are not well defined or distinguished, it can lead to the misinterpretation of results. This is referred to as the measurand problem. The measurand problem can present significant difficulties when the law and not science determines the measurand. This arises when the law requires that a particular quantity be measured. Legal definitions are seldom as rigorous or complete as those utilized in science. Thus, legally defined measurands often fall prey to the measurand problem. An example is the measurement of breath alcohol concentration by infrared spectroscopy. All 50 states authorize such tests but the measurand differs by jurisdiction. This leads to misinterpretation of results in both the forensic and legal communities due to the measurand problem with the consequence that the innocent are convicted and guilty set free. Correct interpretation of breath test results requires that the measurand be properly understood and accounted for. I set forth the varying measurands defined by law, the impact these differing measurands have on the interpretation of breath test results and how the measurand problem can be avoided in the measurement of breath alcohol concentration.

  4. 10 CFR 26.95 - Conducting an initial test for alcohol using a breath specimen.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Conducting an initial test for alcohol using a breath... Specimens for Testing § 26.95 Conducting an initial test for alcohol using a breath specimen. (a) The collector shall perform the initial breath test as soon as practical after the donor indicates that he...

  5. 10 CFR 26.95 - Conducting an initial test for alcohol using a breath specimen.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Conducting an initial test for alcohol using a breath... Specimens for Testing § 26.95 Conducting an initial test for alcohol using a breath specimen. (a) The collector shall perform the initial breath test as soon as practical after the donor indicates that he...

  6. 10 CFR 26.95 - Conducting an initial test for alcohol using a breath specimen.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Conducting an initial test for alcohol using a breath... Specimens for Testing § 26.95 Conducting an initial test for alcohol using a breath specimen. (a) The collector shall perform the initial breath test as soon as practical after the donor indicates that he...

  7. 10 CFR 26.95 - Conducting an initial test for alcohol using a breath specimen.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Conducting an initial test for alcohol using a breath... Specimens for Testing § 26.95 Conducting an initial test for alcohol using a breath specimen. (a) The collector shall perform the initial breath test as soon as practical after the donor indicates that he...

  8. Combined overexpression of genes involved in pentose phosphate pathway enables enhanced D-xylose utilization by Clostridium acetobutylicum.

    PubMed

    Jin, Lin; Zhang, Hui; Chen, Liwen; Yang, Chen; Yang, Sheng; Jiang, Weihong; Gu, Yang

    2014-03-10

    D-Xylose utilization by Clostridium acetobutylicum, an important industrial microorganism used in ABE (Acetone, Butanol and Ethanol) production, has attracted increasing interests. We demonstrated previously that co-overexpression of genes, encoding d-xylose symporter, D-xylose isomerase and xylulokinase, improved D-xylose utilization by C. acetobutylicum (Xiao, H., et al., 2011. Applied and Environmental Microbiology 77, 7886-7895). Here, we further identified genes involved in PPP (Pentose Phosphate Pathway) in C. acetobutylicum and evaluated their contribution to d-xylose utilization. Among all the candidate genes, the CAC1347, CAC1348, CAC1730 and CAC2880 were validated to encode genes tal, tkl, rpe and rpi, four key genes involved in PPP, respectively. The following combined overexpression of these genes conferred a significantly improved xylose-utilizing ability to the recombinant strain, reaching a solvent titer 42% higher than that of the wild-type strain. This finding offers a useful strategy to optimize d-xylose utilization by C. acetobutylicum.

  9. Formation of xylitol and xylitol-5-phosphate and its impact on growth of d-xylose-utilizing Corynebacterium glutamicum strains.

    PubMed

    Radek, Andreas; Müller, Moritz-Fabian; Gätgens, Jochem; Eggeling, Lothar; Krumbach, Karin; Marienhagen, Jan; Noack, Stephan

    2016-08-10

    Wild-type Corynebacterium glutamicum has no endogenous metabolic activity for utilizing the lignocellulosic pentose d-xylose for cell growth. Therefore, two different engineering approaches have been pursued resulting in platform strains harbouring a functional version of either the Isomerase (ISO) or the Weimberg (WMB) pathway for d-xylose assimilation. In a previous study we found for C. glutamicum WMB by-product formation of xylitol during growth on d-xylose and speculated that the observed lower growth rates are due to the growth inhibiting effect of this compound. Based on a detailed phenotyping of the ISO, WMB and the wild-type strain of C. glutamicum, we here show that this organism has a natural capability to synthesize xylitol from d-xylose under aerobic cultivation conditions. We furthermore observed the intracellular accumulation of xylitol-5-phosphate as a result of the intracellular phosphorylation of xylitol, which was particularly pronounced in the C. glutamicum ISO strain. Interestingly, low amounts of supplemented xylitol strongly inhibit growth of this strain on d-xylose, d-glucose and d-arabitol. These findings demonstrate that xylitol is a suitable substrate of the endogenous xylulokinase (XK, encoded by xylB) and its overexpression in the ISO strain leads to a significant phosphorylation of xylitol in C. glutamicum. Therefore, in order to circumvent cytotoxicity by xylitol-5-phosphate, the WMB pathway represents an interesting alternative route for engineering C. glutamicum towards efficient d-xylose utilization.

  10. Mechanism of D-fructose isomerization by Arthrobacter D-xylose isomerase.

    PubMed Central

    Rangarajan, M; Hartley, B S

    1992-01-01

    The mechanism of D-fructose isomerization by Arthrobacter D-xylose isomerase suggested from X-ray-crystallographic studies was tested by detailed kinetic analysis of the enzyme with various metal ions at different pH values and temperatures. At D-fructose concentrations used in commercial processes Mg2+ is the best activator with an apparent dissociation constant of 63 microM; Co2+ and Mn2+ bind more strongly (apparent Kd 20 microM and 10 microM respectively) but give less activity (45% and 8% respectively). Ca2+ is a strict competitive inhibitor versus Mg2+ (Ki 3 microM) or Co2+ (Ki 105 microM). The kinetics show a compulsory order of binding; Co2+ binds first to Site 2 and then to Site 1; then D-fructose binds at Site 1. At normal concentrations Mg2+ binds at Site 1, then D-fructose and then Mg2+ at Site 2. At very high Mg2+ concentrations (greater than 10 mM) the order is Mg2+ at Site 1, Mg2+ at Site 2, then D-fructose. The turnover rate (kcat.) is controlled by ionization of a residue with apparent pKa at 30 degrees C of 6.0 +/- 0.07 (Mg2+) or 5.3 +/- 0.08 (Co2+) and delta H = 23.5 kJ/mol. This appears to be His-219, which is co-ordinated to M[2]; protonation destroys isomerization by displacing M[2]; Co2+ binds more strongly at Site 2 than Mg2+, so competes more strongly against H+. The inhibition constant (Ki) for the two competitive inhibitors 5-thio-alpha-D-glucopyranose and D-sorbitol is invariant with pH, but Km(app.) in the Mg[1]-enzyme is controlled by ionization of a group with pKa 6.8 +/- 0.07 and delta H = 27 kJ/mol, which appears to be His-53. This shows that Km(app.) is a complex constant that includes the rate of the ring-opening step catalysed by His-53, which explains the pH-dependence. In the Mg[1]Mg[2]-enzyme or Co[1]Co[2]-enzyme, the pKa is lower (6.2 +/- 0.1 or 5.6 +/- 0.08) because of the extra adjacent cation. Hence the results fit the previously proposed pathway, but show that the mechanisms differ for Mg2+ and Co2+ and that the rate

  11. 49 CFR 219.206 - FRA access to breath test results.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false FRA access to breath test results. 219.206 Section 219.206 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 219.206 FRA access to breath test results. Documentation of breath test results must be made...

  12. 49 CFR 219.206 - FRA access to breath test results.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false FRA access to breath test results. 219.206 Section 219.206 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 219.206 FRA access to breath test results. Documentation of breath test results must be made...

  13. 49 CFR 219.206 - FRA access to breath test results.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false FRA access to breath test results. 219.206 Section 219.206 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 219.206 FRA access to breath test results. Documentation of breath test results must be made...

  14. 49 CFR 219.206 - FRA access to breath test results.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false FRA access to breath test results. 219.206 Section 219.206 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 219.206 FRA access to breath test results. Documentation of breath test results must be made...

  15. 49 CFR 219.206 - FRA access to breath test results.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false FRA access to breath test results. 219.206 Section 219.206 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 219.206 FRA access to breath test results. Documentation of breath test results must be made...

  16. 46 CFR 197.450 - Breathing gas tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... commencement of diving operations, at the umbilical or underwater breathing apparatus connection point for the... underwater breathing apparatus connection point for the diver, for percentage of oxygen....

  17. Urinary recovery of orally administered chromium 51-labeled EDTA, lactulose, rhamnose, d-xylose, 3-O-methyl-d-glucose, and sucrose in healthy adult male Beagles.

    PubMed

    Frias, Rafael; Steiner, Jörg M; Williams, David A; Sankari, Satu; Westermarck, Elias

    2012-05-01

    Objective-To provide values for gastrointestinal permeability and absorptive function tests (GIPFTs) with chromium 51 ((51)Cr)-labeled EDTA, lactulose, rhamnose, d-xylose, 3-O-methyl-d-glucose, and sucrose in Beagles and to evaluate potential correlations between markers. Animals-19 healthy adult male Beagles. Procedures-A test solution containing 3.7 MBq of (51)Cr-labeled EDTA, 2 g of lactulose, 2 g of rhamnose, 2 g of d-xylose, 1 g of 3-O-methyl-d-glucose, and 8 g of sucrose was administered intragastrically to each dog. Urinary recovery of each probe was determined 6 hours after administration. Results-Mean ± SD (range) percentage urinary recovery was 6.3 ± 1.6% (4.3% to 9.7%) for (51)Cr-labeled EDTA, 3.3 ± 1.1% (1.7% to 5.3%) for lactulose, 25.5 ± 5.0% (16.7% to 36.9%) for rhamnose, and 58.8% ± 11.0% (40.1% to 87.8%) for 3-O-methyl-d-glucose. Mean (range) recovery ratio was 0.25 ± 0.06 (0.17 to 0.37) for (51)Cr-labeled EDTA to rhamnose, 0.13 ± 0.04 (0.08 to 0.23) for lactulose to rhamnose, and 0.73 ± 0.09 (0.60 to 0.90) for d-xylose to 3-O-methyl-d-glucose. Median (range) percentage urinary recovery was 40.3% (31.6% to 62.7%) for d-xylose and 0% (0% to 0.8%) for sucrose. Conclusions and Clinical Relevance-Reference values in healthy adult male Beagles for 6 of the most commonly used GIPFT markers were determined. The correlation between results for (51)Cr-labeled EDTA and lactulose was not as prominent as that reported for humans and cats; thus, investigators should be cautious in the use and interpretation of GIPFTs performed with sugar probes in dogs with suspected intestinal dysbiosis.

  18. Consecutively Preparing D-Xylose, Organosolv Lignin, and Amorphous Ultrafine Silica from Rice Husk

    PubMed Central

    Zhang, Hongxi; Ding, Xuefeng; Wang, Zichen; Zhao, Xu

    2014-01-01

    Rice husk is an abundant agricultural by-product reaching the output of 80 million tons annually in the world. The most common treatment method of rice husk is burning or burying, which caused serious air pollution and resource waste. In order to solve this problem, a new method is proposed to comprehensively utilize the rice husk in this paper. Firstly, the D-xylose was prepared from the semicellulose via dilute acid hydrolysis. Secondly, the lignin was separated via organic solvent pulping from the residue. Finally, the amorphous ultrafine silica was prepared via pyrolysis of the residue produced in the second process. In this way, the three main contents of rice husk (semicellulose, lignin, and silica) are consecutively converted to three fine chemicals, without solid waste produced. The yields of D-xylose and organosolv lignin reach 58.2% and 58.5%, respectively. The purity and specific surface of amorphous ultrafine silica reach 99.92% and 225.20 m2/g. PMID:25140120

  19. Fermentation of D-xylose and L-arabinose to ethanol by Erwinia chrysanthemi

    SciTech Connect

    Tolan, J.S.; Finn, R.K.

    1987-09-01

    Erwinia spp. are gram-negative facultative anaerobes within the family Enterobacteriacae which possess several desirable traits for the conversion of pentose sugars to ethanol, such as the ability to ferment a broad range of carbohydrates and the ease with which they can be genetically modified. Twenty-eight strains of Erwinia carotovora and E. chrysanthemi were screened for the ability to ferment D-xylose to ethanol. E. chrysanthemi B374 was chosen for further study on the basis of its superior (4%) ethanol tolerance. They have characterized the fermentation of D-xylose and L-arabinose by the wild type and mutants which bear plasmids containing the pyruvate decarboxylase gene from Zymomonas mobilis. Expression of the gene markedly increased the yields of ethanol (from 0.7 up to 1.45 mol/mol of xylose) and decreased the yields of formate, acetate, and lactate. However, the cells with pyruvate decarboxylase grew only one-fourth as fast as the wild type and tolerated only 2% ethanol. Alcohol tolerance was stimulated by the addition of yeast extract to the growth medium. Xylose catabolism was characterized by a high saturation constant K/sub s/ (4.5 mM).

  20. 49 CFR 40.277 - Are alcohol tests other than saliva or breath permitted under these regulations?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Are alcohol tests other than saliva or breath... Testing § 40.277 Are alcohol tests other than saliva or breath permitted under these regulations? No.... Only saliva or breath for screening tests and breath for confirmation tests using approved devices...

  1. 49 CFR 40.277 - Are alcohol tests other than saliva or breath permitted under these regulations?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false Are alcohol tests other than saliva or breath... Testing § 40.277 Are alcohol tests other than saliva or breath permitted under these regulations? No.... Only saliva or breath for screening tests and breath for confirmation tests using approved devices...

  2. 49 CFR 40.277 - Are alcohol tests other than saliva or breath permitted under these regulations?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false Are alcohol tests other than saliva or breath... Testing § 40.277 Are alcohol tests other than saliva or breath permitted under these regulations? No.... Only saliva or breath for screening tests and breath for confirmation tests using approved devices...

  3. 49 CFR 40.277 - Are alcohol tests other than saliva or breath permitted under these regulations?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false Are alcohol tests other than saliva or breath... Testing § 40.277 Are alcohol tests other than saliva or breath permitted under these regulations? No.... Only saliva or breath for screening tests and breath for confirmation tests using approved devices...

  4. 49 CFR 40.277 - Are alcohol tests other than saliva or breath permitted under these regulations?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 false Are alcohol tests other than saliva or breath... Testing § 40.277 Are alcohol tests other than saliva or breath permitted under these regulations? No.... Only saliva or breath for screening tests and breath for confirmation tests using approved devices...

  5. Assessment of the 14C-Glycocholic Acid Breath Test

    PubMed Central

    James, O. F. W.; Agnew, J. E.; Bouchier, I. A. D.

    1973-01-01

    The 1-(14C)-glycine-glycocholic-acid breath test has been performed on 104 subjects and a normal range established. Abnormal results due to bacterial deconjugation of bile salts were found not only in patients with the “contaminated bowel” syndrome and in those with ileal resection but also in a third group, patients with cholangitis. Abnormal results were also found in patients with gastrocolic fistula and staphylococcal enterocolitis, while mildly abnormal results were also found in some patients with liver disease. PMID:4718834

  6. 4-O-beta-D-galactopyranosyl-D-xylose: a new synthesis and application to the evaluation of intestinal lactase.

    PubMed

    Rivera-Sagredo, A; Fernández-Mayoralas, A; Jiménez-Barbero, J; Martín-Lomas, M; Villanueva, D; Aragón, J J

    1992-04-10

    4-O-beta-D-Galactopyranosyl-D-xylose (2) was prepared from benzyl 2,3-O-isopropylidene-beta-D-xylopyranoside by glycosylation with 2,3,4,6-tetra-O-benzoyl-alpha-D-galactopyranosyl bromide and subsequent deprotection. Compound 2 was hydrolyzed in vitro by intestinal lactase; the Vmax was 25% of that with lactose and the Km was 370mM (cf. 27mM for lactose). Oral administration of 2 suckling rats led to urinary excretion of D-xylose which could be estimated colorimetrically. PMID:1516083

  7. A 20-minute breath test for helicobacter pylori

    SciTech Connect

    Marshall, B.J.; Plankey, M.W.; Hoffman, S.R.; Boyd, C.L.; Dye, K.R.; Frierson, H.F. Jr.; Guerrant, R.L.; McCallum, R.W. )

    1991-04-01

    In this study, we evaluated a simplified rapid {sup 14}C-urea breath test for the diagnosis of Helicobacter pylori. Fasting patients undergoing initial assessment for H. pylori drank 5 microCi of {sup 14}C-urea in 20 ml of water. Breath was collected at intervals for 30 min. Samples were counted in a beta-counter, and the results were expressed as counts per minute (cpm). In the same week, patients underwent endoscopy, and a blinded investigator examined biopsy samples of gastric mucosa by culture and histology for H. pylori. There were 49 H. pylori-negative (HP-) and 104 H. pylori-positive (HP+) patients in the study. HP+ patients expired a mean of 4398 cpm (SD 2468) per mmol CO{sub 2} in a sample taken 20 min after ingestion of the isotope. In contrast, HP--patients expired only 340 cpm (SD 196). If the mean +3 SD of HP- patients was used as a cutoff value, the 20-minute sample gave a sensitivity of 97% and a specificity of 100% for detecting H. pylori. The radiation exposure from this test is less than 1% of that received from an upper gastrointestinal series, and the short collection time makes it both convenient and cost effective.

  8. Breath testing with a mid-IR laser spectrometer

    NASA Astrophysics Data System (ADS)

    Namjou, Khosrow; McCann, Patrick J.; Potter, William T.

    1999-10-01

    A mid-IR tunable diode laser absorption spectrometer (TDLAS) equipped with a multiple-pass gas cell was used to measure breath samples from a number of student volunteers at the University of Oklahoma. Test subjects included one to two pack-a-day cigarette smokers and non-smokers. The concentrations of four different molecules, N2O, 12CO2, 13CO2 and CO, were measured by each laser scan in the 2206.1 cm-1 to 2207 cm-1 spectral range. The average concentration of nitrous oxide (N2O) increased slightly for smokers versus non-smokers and was generally higher (12%) than the approximately 255 ppm concentration measured in ambient air. Carbon monoxide concentrations, however, were much higher in breath samples from cigarette smokers. Ambient concentrations of carbon monoxide, approximately 0.4 ppm, increased from approximately 1.0 ppm in non-smokers to levels over 13.4 ppm in smokers. These measurements provide clear evidence of the well-known effect that cigarette smoking has on replacing oxygen with carbon monoxide in human hemoglobin. Carbon dioxide concentrations of smokers were generally decreased by approximately 12%. Mid-IR laser measurements also provided 13CO2/12CO2 isotope ratio values, and smokers had a approximately 30% greater concentration of isotopic 13C in their breath. The possible mechanisms for 13CO2 isotopic increases are at present unknown. Overall, long-path TDL spectroscopy of exhalation products is a uniquely powerful tool. The TDL systems can be used for noninvasive diagnosis of a wide range of metabolisms and pathologies.

  9. The effects of water on beta-D-xylose condensation reactions.

    PubMed

    Dong, Haitao; Nimlos, Mark R; Himmel, Michael E; Johnson, David K; Qian, Xianghong

    2009-07-30

    Car-Parrinello-based ab initio molecular dynamics simulations (CPMD) combined with metadynamics (MTD) simulations were used to determine the reaction energetics for the beta-D-xylose condensation reaction to form beta-1,4-linked xylobiose in a dilute acid solution. Protonation of the hydroxyl group on the xylose molecule and the subsequent breaking of the C-O bond were found to be the rate-limiting step during the xylose condensation reaction. Water and water structure was found to play a critical role in these reactions due to the proton's high affinity for water molecules. The reaction free energy and reaction barrier were determined using CPMD-MTD. We found that solvent reorganization due to proton partial desolvation must be taken into account in order to obtain the correct reaction activation energy. Our calculated reaction free energy and reaction activation energy compare well with available experimental results. PMID:19572686

  10. Molecular cloning, DNA structure and expression of the Escherichia coli D-xylose isomerase.

    PubMed Central

    Briggs, K A; Lancashire, W E; Hartley, B S

    1984-01-01

    The D-xylose isomerase (EC 5.3.1.5) gene from Escherichia coli was cloned and isolated by complementation of an isomerase-deficient E. coli strain. The insert containing the gene was restriction mapped and further subcloning located the gene in a 1.6-kb Bg/II fragment. This fragment was sequenced by the chain termination method, and showed the gene to be 1002 bp in size. The Bg/II fragment was cloned into a yeast expression vector utilising the CYCl yeast promoter. This construct allowed expression in E. coli grown on xylose but not glucose suggesting that the yeast promoter is responding to the E. coli catabolite repression system. No expression was detected in yeast from this construct and this is discussed in terms of the upstream region in the E. coli insert with suggestions of how improved constructs may permit achievement of the goal of a xylose-fermenting yeast. PMID:6325179

  11. Reactivity of D-fructose and D-xylose in acidic media in homogeneous phases.

    PubMed

    Fusaro, Maxime B; Chagnault, Vincent; Postel, Denis

    2015-05-29

    Chemistry development of renewable resources is a real challenge. Carbohydrates from biomass are complex and their use as substitutes for fossil materials remains difficult (European involvement on the incorporation of 20% raw material of plant origin in 2020). Most of the time, the transformation of these polyhydroxylated structures are carried out in acidic conditions. Recent reviews on this subject describe homogeneous catalytic transformations of pentoses, specifically toward furfural, and also the transformation of biomass-derived sugars in heterogeneous conditions. To complete these informations, the objective of this review is to give an overview of the structural variety described during the treatment of two monosaccharides (D-Fructose and D-xylose) in acidic conditions in homogeneous phases. The reaction mechanisms being not always determined with certainty, we will also provide a brief state of the art regarding this. PMID:25889471

  12. Exhaled breath for drugs of abuse testing - evaluation in criminal justice settings.

    PubMed

    Beck, Olof

    2014-01-01

    Exhaled breath is being developed as a possible specimen for drug testing based on the collection of aerosol particles originating from the lung fluid. The present study was aimed to evaluate the applicability of exhaled breath for drugs of abuse testing in criminal justice settings. Particles in exhaled breath were collected with a new device in parallel with routine urine testing in two Swedish prisons, comprising both genders. Urine screening was performed according to established routines either by dipstick or by immunochemical methods at the Forensic Chemistry Laboratory and confirmations were with mass spectrometry methods. A total of 247 parallel samples were studied. Analysis of exhaled breath samples was done with a sensitive mass spectrometric method and identifications were made according to forensic standards. In addition tested subjects and personnel were asked to fill in a questionnaire concerning their views about drug testing. In 212 cases both the urine and breath testing were negative, and in 22 cases both urine and breath were positive. Out of 6 cases where breath was negative and urine positive 4 concerned THC. Out of 7 cases where, breath was positive and urine negative 6 concerned amphetamine. Detected substances in breath comprised: amphetamine, methamphetamine, THC, methylphenidate, buprenorphine, 6-acetylmorphine, cocaine, benzoylecgonine, diazepam and tramadol. Both the prison inmates and staff members reported breath testing to be preferable due to practical considerations. The results of this study documented that drug testing using exhaled breath provided as many positives as urine testing despite an expected shorter detection window, and that the breath sampling procedure was well accepted and provided practical benefits reported both by the prison inmates and testing personnel.

  13. 10 CFR 26.95 - Conducting an initial test for alcohol using a breath specimen.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Conducting an initial test for alcohol using a breath specimen. 26.95 Section 26.95 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for Testing § 26.95 Conducting an initial test for alcohol using a breath specimen. (a)...

  14. Aspiration tests in aqueous foam using a breathing simulator

    SciTech Connect

    Archuleta, M.M.

    1995-12-01

    Non-toxic aqueous foams are being developed by Sandia National Laboratories (SNL) for the National Institute of Justice (NIJ) for use in crowd control, cell extractions, and group disturbances in the criminal justice prison systems. The potential for aspiration of aqueous foam during its use and the resulting adverse effects associated with complete immersion in aqueous foam is of major concern to the NIJ when examining the effectiveness and safety of using this technology as a Less-Than-Lethal weapon. This preliminary study was designed to evaluate the maximum quantity of foam that might be aspirated by an individual following total immersion in an SNL-developed aqueous foam. A.T.W. Reed Breathing simulator equipped with a 622 Silverman cam was used to simulate the aspiration of an ammonium laureth sulfate aqueous foam developed by SNL and generated at expansion ratios in the range of 500:1 to 1000:1. Although the natural instinct of an individual immersed in foam is to cover their nose and mouth with a hand or cloth, thus breaking the bubbles and decreasing the potential for aspiration, this study was performed to examine a worst case scenario where mouth breathing only was examined, and no attempt was made to block foam entry into the breathing port. Two breathing rates were examined: one that simulated a sedentary individual with a mean breathing rate of 6.27 breaths/minute, and one that simulated an agitated or heavily breathing individual with a mean breathing rate of 23.7 breaths/minute. The results of this study indicate that, if breathing in aqueous foam without movement, an air pocket forms around the nose and mouth within one minute of immersion.

  15. Operation and testing of Mark 10 Mod 3 underwater breathing apparatus

    NASA Technical Reports Server (NTRS)

    Milwee, W. I., Jr.

    1972-01-01

    Performance tests on a closed circuit, mixed gas underwater breathing apparatus are reported. The equipment is designed to provide a minimum diving duration of four hours at 1500 ft below sea surface; it senses oxygen partial pressure in the breathing gas mix and controls oxygen content of the breathing gas within narrow limits about a preset value. The breathing circuit subsystem provides respirable gas to the diver and removes carbon dioxide and moisture from the expired gas. Test results indicate undesirable variations in oxygen partial pressure with oxygen addition and insufficient carbon dioxide absorption.

  16. (13) C Breath Tests Are Feasible in Patients With Extracorporeal Membrane Oxygenation Devices.

    PubMed

    Bednarsch, Jan; Menk, Mario; Malinowski, Maciej; Weber-Carstens, Steffen; Pratschke, Johann; Stockmann, Martin

    2016-07-01

    Temporary extracorporeal membrane oxygenation (ECMO) has been established as an essential part of therapy in patients with pulmonary or cardiac failure. As physiological gaseous exchange is artificially altered in this patient group, it is debatable whether a (13) C-breath test can be carried out. In this proof of technical feasibility report, we assess the viability of the (13) C-breath test LiMAx (maximum liver function capacity) in patients on ECMO therapy. All breath probes for the test device were obtained directly via the membrane oxygenator. Data of four patients receiving liver function assessment with the (13) C-breath test LiMAx while having ECMO therapy were analyzed. All results were compared with validated scenarios of the testing procedures. The LiMAx test could successfully be carried out in every case without changing ECMO settings. Clinical course of the patients ranging from multiorgan failure to no sign of liver insufficiency was in accordance with the results of the LiMAx liver function test. The (13) C-breath test is technically feasible in the context of ECMO. Further evaluation of (13) C-breath test in general would be worthwhile. The LiMAx test as a (13) C-breath test accessing liver function might be of particular predictive interest if patients with ECMO therapy develop multiorgan failure. PMID:26527580

  17. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to anti-inflammatory therapy, as an adjunct to established clinical and laboratory assessments of...

  18. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to anti-inflammatory therapy, as an adjunct to established clinical and laboratory assessments of...

  19. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to anti-inflammatory therapy, as an adjunct to established clinical and laboratory assessments of...

  20. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to anti-inflammatory therapy, as an adjunct to established clinical and laboratory assessments of...

  1. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to anti-inflammatory therapy, as an adjunct to established clinical and laboratory assessments of...

  2. Production of xylitol from D-xylose by recombinant Lactococcus lactis.

    PubMed

    Nyyssölä, Antti; Pihlajaniemi, Anne; Palva, Airi; von Weymarn, Niklas; Leisola, Matti

    2005-07-21

    The D-xylose reductase from Pichia stipitis CBS 5773 and the xylose transporter from Lactobacillus brevis ATCC 8287 were expressed in active form in Lactococcus lactis NZ9800. Xylitol production was investigated using non-growing recombinant cells in high cell-density under microaerobic conditions in the presence of xylose and glucose. Besides xylose, the recombinant strain with xylose reductase activity reduced l-arabinose and D-ribose in significant extent to the corresponding pentitols. The ratio of xylitol produced per glucose consumed was almost 10-fold higher under glucose limitation than the ratio in the presence of excess initial glucose. The co-expression of the xylose transporter with the xylose reductase did not increase the efficiency of xylitol production appreciably when compared to the strain in which only the xylose reductase gene was expressed. A fed-batch experiment with high initial xylose concentration (160 gl(-1)) under glucose limitation was carried out using the strain co-expressing xylose reductase and xylose transporter genes. The xylitol yield from xylose was 1.0 mol mol(-1) and the ratio of xylitol produced per glucose consumed was 2.5 mol mol(-1). The volumetric productivity was 2.72 gl(-1)h(-1) at 20 h. Of the xylose initially present, 34% was consumed. Analysis of the fermentation metabolites revealed a shift from homolactic to mixed acid fermentation at early stages of the experiment.

  3. Phase V of the single-breath washout test

    NASA Technical Reports Server (NTRS)

    Nichol, G. M.; Michels, D. B.; Guy, H. J. B.

    1982-01-01

    A downward-deflecting phase V is often seen following the terminal rise (phase IV) in single-breath washout tests. To investigate the nature of phase V, experiments using simultaneous washouts of N2 and tracer boluses of Ar were performed on eight normal nonsmoking subjects aged 27-41 who exhibited a phase V. Phase V is found to occur in all subjects at expiratory flow rates between 0.1 and 2.0 l/sec shortly after expiration became flow limited. Volumes of both phases IV and V increase with increasing flow rate. The difference between the exhaled volumes at which flow became limited and phase V appeared is shown to be approximately equal to the anatomic dead space. Results support a model of lung emptying in a gravitational field in which flow limitation occurs first in the lower lung regions and then progresses toward the upper regions, causing phase IV. A decrease in the amount of flow from the upper relative to the lower regions after all regions have become flow limited then causes phase V.

  4. Locating Active-site Hydrogen Atoms in D-Xylose Isomerase: Time-of-Flight Neutron Diffraction.

    SciTech Connect

    Bunick, G J

    2006-01-01

    Time-of-flight neutron diffraction has been used to locate hydrogen atoms that define the ionization states of amino acids in crystals of D-xylose isomerase. This enzyme, from Streptomyces rubiginosus, is one of the largest enzymes studied to date at high resolution (1.8 ) by this method. We have determined the position and orientation of a metal ion-bound water molecule that is located in the active site of the enzyme; this water has been thought to be involved in the isomerization step in which D-xylose is converted to D-xylulose or D-glucose to D-fructose. It is shown to be water (rather than a hydroxyl group) under the conditions of measurement (pH 8.0). Our analyses also reveal that one lysine probably has an -NH2 terminal group (rather than NH3+). The ionization state of each histidine residue was also determined.

  5. Breath hydrogen test in infants and children with blind loop syndrome.

    PubMed

    Nose, O; Kai, H; Harada, T; Ogawa, M; Maki, I; Tajiri, H; Kanaya, S; Kimura, S; Shimizu, K; Yabuuchi, H

    1984-06-01

    Breath hydrogen production after oral lactose loading was examined in infants and children with stagnant loop syndrome, blind loop syndrome, or both. All six infants under 3 years of age had bacteriological evidence of small intestinal colonization. The characteristics of the breath hydrogen test in this syndrome are: (a) extremely high basal excretion of breath hydrogen (after overnight fasting); (b) an earlier and greater breath hydrogen value (0.293 +/- 0.201 ml/min/m2: mean +/- SD) after oral lactose administration than formed in lactose malabsorption alone (0.050 +/- 0.041 ml/min/m2); and (c) the observation of a sustained hydrogen rise over several hours. This investigation demonstrated that the breath hydrogen test is a promising and noninvasive tool for diagnosing blind (or stagnant) loop syndrome.

  6. Stability of Arthrobacter D-xylose isomerase to denaturants and heat.

    PubMed

    Rangarajan, M; Asboth, B; Hartley, B S

    1992-08-01

    There was no inactivation of Mg(2+)-containing Arthrobacter D-xylose isomerase up to 1 h in 0-8 M-urea at 22 degrees C, but over this range there was rapid reversible dissociation into fully active dimers with a midpoint around 4 M-urea, as shown by gradient urea gels with an activity stain, and by ion-exchange chromatography and gel filtration in urea buffers. These dimers must have the A-B* conformation, since the tetramer could dissociate into A-A*, A-B or A-B* dimer conformations, but only residues across the A-B* interface contribute to the active site. The kinetics of inactivation of the Mg(2+)-containing enzyme in 8 M-urea at higher temperatures suggest a partially unfolded Mg-A-B* dimer intermediate with 50% activity, followed by irreversible inactivation coincident with the appearance of unfolded monomer. In 0-4 M guanidinium chloride, a similar reversible dissociation into active dimers occurs, but activity falls, suggesting that A-A* and/or A-B dimers might be part of the mixture. Low concentrations of SDS also give active dimers leading to unfolded monomers, but SDS above 1% (w/v) provides relative stabilization. The apoenzyme is least thermostable (t 1/2 at 80 degrees C, pH 7, = 0.06 h) but Mg2+ stabilizes strongly (t 1/2 = 5.5 h) and Co2+ even more so. Competitive inhibitors or substrates provide a small further stabilization, but this effect is more marked at 80 degrees C, pH 5.5. Together with a marked decrease in optimum pH with temperature, this allows batch isomerizations of glucose under these conditions that produce clean but sweeter syrups. PMID:1497626

  7. Role of D-ribose as a cometabolite in D-xylose metabolism by Saccharomyces cerevisiae.

    PubMed Central

    van Zyl, C; Prior, B A; Kilian, S G; Brandt, E V

    1993-01-01

    The influence of D-ribose as a cosubstrate on the uptake and metabolism of the non-growth substrate D-xylose by Saccharomyces cerevisiae ATCC 26602 was investigated. Xylose was taken up by means of low- and high-affinity glucose transport systems. In cells exposed for 2 days to a mixture of xylose and ribose, only the high-affinity system could be detected. Glucose strongly inhibited the transport of xylose by both systems. Starvation or exposure to either xylose or ribose resulted in inactivation of xylose transport, which did not occur in the presence of a mixture of ribose and xylose. A constitutive non-glucose-repressible NADPH2-dependent xylose reductase with a specific activity of ca. 5 mU/mg of protein that converted xylose to xylitol was present in a glucose-grown culture. No activity converting xylitol to xylulose or vice versa was found in crude extracts. Both xylose and ribose were converted to their corresponding polyols, xylitol and ribitol, as indicated by 13C nuclear magnetic resonance spectroscopy. Furthermore, ethanol was detected, and this implied that pathways for the complete catabolism of xylose and ribose exist. However, the NADPH2 required for the conversion of xylose to xylitol is apparently not supplied by the pentose phosphate pathway since the ethanol produced from D-[1-13C]xylose was labelled only in the C-2 position. Acetic acid was produced from ribose and may assist in the conversion of xylose to xylitol by cycling NADPH2. PMID:8517743

  8. The Effects of Gastroesophageal Reflux Disease on Forensic Breath Alcohol Testing.

    PubMed

    Booker, James L; Renfroe, Kathryn

    2015-11-01

    Fifteen test subjects, 10 of whom were diagnosed with gastroesophageal reflux disease (GERD), were dosed with alcohol to BACs above 0.150 g/dL. Blood and breath assays taken at 20-min intervals for 8 h after dosing demonstrated close agreement between postabsorptive BAC and BrAC values. Three subjects exhibited elevated breath alcohol concentrations up to 0.105 g/dL during the absorptive phase that were apparently due to the passage of gastric alcohol through the lower esophageal sphincter not attributable to eruction or regurgitation. The effect of gastric alcohol was not consistently proportional to the amount of unabsorbed gastric alcohol. Absorption of alcohol in the esophagus explains the nonproportionality. Breath samples contaminated by GERD-related alcohol leakage from the stomach into a breath sample were found only when there was a high concentration of alcohol in the stomach. When contaminated breath samples were encountered, they were irreproducible in magnitude.

  9. Critical appraisal of 13C breath tests for microsomal liver function: aminopyrine revisited.

    PubMed

    Pijls, Kirsten E; de Vries, Hanne; Nikkessen, Suzan; Bast, Aalt; Wodzig, Will K W H; Koek, Ger H

    2014-04-01

    As liver diseases are a major health problem and especially the incidence of metabolic liver diseases like non-alcoholic fatty liver disease (NAFLD) is rising, the demand for non-invasive tests is growing to replace liver biopsy. Non-invasive tests such as carbon-labelled breath tests can provide a valuable contribution to the evaluation of metabolic liver function. This review aims to critically appraise the value of the (13) C-labelled microsomal breath tests for the evaluation of metabolic liver function, and to discuss the role of cytochrome P450 enzymes in the metabolism of the different probe drugs, especially of aminopyrine. Although a number of different probe drugs have been used in breath tests, the perfect drug to assess the functional metabolic capacity of the liver has not been found. Data suggest that both the (13) C(2) -aminopyrine and the (13) C-methacetin breath test can play a role in assessing the capacity of the microsomal liver function and may be useful in the follow-up of patients with chronic liver diseases. Furthermore, CYP2C19 seems to be an important enzyme in the N-demethylation of aminopyrine, and polymorphisms in this gene may influence breath test values, which should be kept in mind when performing the (13) C(2) -aminopyrine breath test in clinical practice.

  10. Breath alcohol test precision: an in vivo vs. in vitro evaluation.

    PubMed

    Gullberg, R G

    1989-12-01

    Random error is associated with breath alcohol measurements, as with all analytical methods. The total random uncertainty of a group of n measurements is typically determined by computing the standard deviation and requiring it to be less than some appropriate level (i.e., +/- 0.0042 g/210 l). The total random uncertainty has two primary sources; the instrumental method and the sample source. These are typically inseparable values. In breath alcohol testing the two primary sample sources are simulators and human breath. The present study evaluates ten groups of simulator samples consisting of ten measurements each on BAC Verifier Datamaster instruments. The data also includes ten breath alcohol measurements from each of 21 individuals following alcohol consumption. The range of standard deviations for the simulator samples was 0.0003-0.0022 g/210 l. The range of standard deviations for the human breath samples was 0.0015-0.0089 g/210 l. Two statistics that test for homogeneity for variances were applied. The simulator samples resulted in a Cochran's C test of 0.5000 and an Fmax test of 48.9. The human breath samples resulted in a Cochran's C test of 0.1519 and an Fmax test of 27.3. All were significant at P less than 0.001. The statistical tests demonstrated that the intragroup variability among the human subjects was comparable to the intragroup variability among the simulator samples. The data also demonstrates that the sample source (simulator or human) is probably the largest contributor to total random uncertainty. Therefore, when duplicate breath alcohol testing from individuals shows variability in the second decimal place the cause is differences in breath samples provided and not instrumental imprecision.

  11. (13)C-Breath testing in animals: theory, applications, and future directions.

    PubMed

    McCue, Marshall D; Welch, Kenneth C

    2016-04-01

    The carbon isotope values in the exhaled breath of an animal mirror the carbon isotope values of the metabolic fuels being oxidized. The measurement of stable carbon isotopes in carbon dioxide is called (13)C-breath testing and offers a minimally invasive method to study substrate oxidation in vivo. (13)C-breath testing has been broadly used to study human exercise, nutrition, and pathologies since the 1970s. Owing to reduced use of radioactive isotopes and the increased convenience and affordability of (13)C-analyzers, the past decade has witnessed a sharp increase in the use of breath testing throughout comparative physiology--especially to answer questions about how and when animals oxidize particular nutrients. Here, we review the practical aspects of (13)C-breath testing and identify the strengths and weaknesses of different methodological approaches including the use of natural abundance versus artificially-enriched (13)C tracers. We critically compare the information that can be obtained using different experimental protocols such as diet-switching versus fuel-switching. We also discuss several factors that should be considered when designing breath testing experiments including extrinsic versus intrinsic (13)C-labelling and different approaches to model nutrient oxidation. We use case studies to highlight the myriad applications of (13)C-breath testing in basic and clinical human studies as well as comparative studies of fuel use, energetics, and carbon turnover in multiple vertebrate and invertebrate groups. Lastly, we call for increased and rigorous use of (13)C-breath testing to explore a variety of new research areas and potentially answer long standing questions related to thermobiology, locomotion, and nutrition. PMID:26660654

  12. (13)C-Breath testing in animals: theory, applications, and future directions.

    PubMed

    McCue, Marshall D; Welch, Kenneth C

    2016-04-01

    The carbon isotope values in the exhaled breath of an animal mirror the carbon isotope values of the metabolic fuels being oxidized. The measurement of stable carbon isotopes in carbon dioxide is called (13)C-breath testing and offers a minimally invasive method to study substrate oxidation in vivo. (13)C-breath testing has been broadly used to study human exercise, nutrition, and pathologies since the 1970s. Owing to reduced use of radioactive isotopes and the increased convenience and affordability of (13)C-analyzers, the past decade has witnessed a sharp increase in the use of breath testing throughout comparative physiology--especially to answer questions about how and when animals oxidize particular nutrients. Here, we review the practical aspects of (13)C-breath testing and identify the strengths and weaknesses of different methodological approaches including the use of natural abundance versus artificially-enriched (13)C tracers. We critically compare the information that can be obtained using different experimental protocols such as diet-switching versus fuel-switching. We also discuss several factors that should be considered when designing breath testing experiments including extrinsic versus intrinsic (13)C-labelling and different approaches to model nutrient oxidation. We use case studies to highlight the myriad applications of (13)C-breath testing in basic and clinical human studies as well as comparative studies of fuel use, energetics, and carbon turnover in multiple vertebrate and invertebrate groups. Lastly, we call for increased and rigorous use of (13)C-breath testing to explore a variety of new research areas and potentially answer long standing questions related to thermobiology, locomotion, and nutrition.

  13. Optimizing Analysis of Stable Isotope Breath Tests to Estimate Gastric Emptying of Solids

    PubMed Central

    Odunsi, Suwebatu T.; Camilleri, Michael; Szarka, Lawrence A.; Zinsmeister, Alan R.

    2009-01-01

    Breath tests using 13C-substrates have been proposed for the measurement of gastric emptying (GE). The mathematical analysis of the breath 13CO2 excretion that most accurately predicts GE t1/2 from simultaneous scintigraphy is unresolved. Aim To compare 5 mathematical methods to estimate GE t½ by breath test (BT) with t½ from simultaneous scintigraphy. Methods Data acquired from a dual-labeled solid-liquid meal containing 99mTc sulfur colloid and 13C-Spirulina platensis from 57 healthy volunteers were used to compare 4 mathematical methods reported in the literature (Ghoos method; generalized linear regression [Viramontes]; linear regression [Szarka]; Wagner-Nelson method) and the total cumulative breath 13CO2 excretion with ≥ 12 breath samples collected over at least 4 hours. The concordance correlation coefficient (CCC) for the t½ results obtained with each method using breath test data was compared with the results obtained with scintigraphy. Results The linear regression and generalized linear regression methods used 5 samples at 45, 90, 120, 150 and 180 minutes. All methods, except for the Wagner-Nelson method, resulted in mean GE t½ that approximated t½ obtained with scintigraphy. The highest CCC was observed with the linear regression method. Simple cumulative excretion of breath 13CO2 provides a better CCC than the Ghoos method. Conclusion The linear regression and generalized linear regression methods (which also require relatively few breath samples) provide the most accurate analyses of breath 13CO2 excretion in stable isotope GEBT. PMID:19309440

  14. sup 14 C-urea breath test for the detection of Helicobacter pylori

    SciTech Connect

    Veldhuyzen van Zanten, S.J.; Tytgat, K.M.; Hollingsworth, J.; Jalali, S.; Rshid, F.A.; Bowen, B.M.; Goldie, J.; Goodacre, R.L.; Riddell, R.H.; Hunt, R.H. )

    1990-04-01

    The high urease activity of Helicobacter pylori can be used to detect this bacterium by noninvasive breath tests. We have developed a {sup 14}C-urea breath test which uses 5 microCi {sup 14}C with 50 mg nonradioactive urea. Breath samples are collected at baseline and every 30 min for 2 h. Our study compared the outcome of the breath test to the results of histology and culture of endoscopically obtained gastric biopsies in 84 patients. The breath test discriminated well between the 50 positive patients and the 34 patients negative for Helicobacter pylori: the calculated sensitivity was 100%, specificity 88%, positive predictive value 93%, and negative predictive value 100%. Treatment with bismuth subsalicylate and/or ampicillin resulted in lower counts of exhaled {sup 14}CO{sub 2} which correlated with histological improvement in gastritis. The {sup 14}C-urea breath test is a better gold standard for the detection of Helicobacter pylori than histology and/or culture.

  15. The Effectiveness of Daily Mindful Breathing Practices on Test Anxiety of Students

    PubMed Central

    Cho, Hyunju; Ryu, Seokjin; Noh, Jeeae; Lee, Jongsun

    2016-01-01

    The present study examined the effectiveness of daily mindful breathing practices on test anxiety of university students. A total of 36 participants were randomly assigned to one of three conditions: a training mindful breathing condition (n = 12), a training cognitive reappraisal condition (contrast group, n = 12), and a non-training condition (control group, n = 12). Each of the participants trained by themselves for 6 days after they had taken one session of education for mindful or cognitive reappraisal practices. They wrote their experiences on daily worksheets and sent it by mobile with taking pictures that were confirmed by the researcher. Before and after training, each of the participants completed a questionnaire to assess: test anxiety, positive thought, and positive affect. The results of the study showed that both mindful breathing practice and cognitive reappraisal practice yielded large effect sizes in reducing test anxiety. In addition, the mindful breathing condition scored significantly higher on positive thoughts than the cognitive reappraisal and control conditions. The findings of this study suggest that both daily mindful breathing and cognitive reappraisal practices were effective in reducing test anxiety; however, mindful breathing increased positive automatic thoughts to a greater extent than cognitive reappraisal. PMID:27764151

  16. Can handling E85 motor fuel cause positive breath alcohol test results?

    PubMed

    Ran, Ran; Mullins, Michael E

    2013-09-01

    Hand-held breath alcohol analyzers are widely used by police in traffic stops of drivers suspected of driving while intoxicated (DWI). E85 is a motor fuel consisting of 85% ethanol and 15% gasoline or other hydrocarbons, and is available at nearly 2,600 stations in the USA. We sought to determine whether handling E85 fuel could produce measurable breath alcohol results using a hand-held analyzer and to see if this would be a plausible explanation for a positive breath alcohol test. Five healthy adult subjects dispensed or transferred 8 US gallons of E85 fuel in each of four scenarios. We measured breath alcohol concentration in g/210 L of exhaled breath using the BACTrack S50 at 0, 2, 4, 6, 8, 10, 15 and 20 min after each fuel-handling scenario. Most of the subjects had no detectable breath alcohol after handling E85 motor fuel. Transient elevations (0.02-0.04 g/210 L) in breath alcohol measurement occurred up to 6 min after handling E85 in a minority of subjects. We conclude that it is unlikely that handling E85 motor fuel would result in erroneous prosecution for DWI. PMID:23843422

  17. Can handling E85 motor fuel cause positive breath alcohol test results?

    PubMed

    Ran, Ran; Mullins, Michael E

    2013-09-01

    Hand-held breath alcohol analyzers are widely used by police in traffic stops of drivers suspected of driving while intoxicated (DWI). E85 is a motor fuel consisting of 85% ethanol and 15% gasoline or other hydrocarbons, and is available at nearly 2,600 stations in the USA. We sought to determine whether handling E85 fuel could produce measurable breath alcohol results using a hand-held analyzer and to see if this would be a plausible explanation for a positive breath alcohol test. Five healthy adult subjects dispensed or transferred 8 US gallons of E85 fuel in each of four scenarios. We measured breath alcohol concentration in g/210 L of exhaled breath using the BACTrack S50 at 0, 2, 4, 6, 8, 10, 15 and 20 min after each fuel-handling scenario. Most of the subjects had no detectable breath alcohol after handling E85 motor fuel. Transient elevations (0.02-0.04 g/210 L) in breath alcohol measurement occurred up to 6 min after handling E85 in a minority of subjects. We conclude that it is unlikely that handling E85 motor fuel would result in erroneous prosecution for DWI.

  18. [The diagnostic value of the aminophenazone breath test in chronic liver diseases].

    PubMed

    Sensing, H; Treutler, J; Haustein, K O; Hüller, G

    1991-09-01

    In 230 patients (90 females, 140 males aged between 20 and 73 years, average age 47.8 years) with and without exception histologically and/or laparoscopically ascertained chronic liver diseases (degenerative damages of liver parenchyma in 45, fatty liver stage I in 28, fatty liver stage II in 36, cholangiohepatitis in 4, chronic persisting hepatitis in 31, chronic active hepatitis in 57 and liver cirrhosis in 59 cases) the incorporation of the aminophenazon breathing test in the so-called laboratory chemical liver spectrum was controlled. The restriction of the microsomal biotransformation established by means of the aminophenazon breathing test behaved parallel to the degree of severity of the disease. The aminophenazon breathing test was performed in the modification after Haustein and Schenker (1985). The largest delays in the decomposition were found in the complete cirrhotic transformation of the liver. The unequivocally pathologic result of the aminophenazon breathing test in severe irreversible damages of the liver parenchyma was confirmed by the formation of correlations with parameters of the conventional laboratory spectrum of the liver. Thus the restriction of the performance of the synthesis of the liver for coagulation factors and albumins was parallel to the loss of function of the mixed functional oxidases. In all patients with chronic liver diseases a connection between the value of the thromboplastin time (Quick's test) and result of the breathing test was found. Positive linear correlation between serum albumin and results of the breathing test could also be proved particularly in the group of the severe chronic inflammatory liver diseases. In chronic fibrosing liver diseases there were positive inverse correlations between gamma-globulin concentration in the serum and thymol turbidity test on the one hand as well as the aminophenazon breathing test on the other. There were no correlations between liver enzyme and aminophenazon breathing test. The

  19. The relationship between aminopyrine breath test and severity of liver disease in cirrhosis

    SciTech Connect

    Morelli, A.; Narducci, F.; Pelli, M.A.; Farroni, F.; Vedovelli, A.

    1981-08-01

    Twenty-two patients with cirrhosis were evaluated by the 2 hr.-(C14)-aminopyrine breath test, the conventional liver tests and two systems for grading the severity of liver disease. Twenty-three patients with noncirrhotic liver disease and 15 controls were also studied. Reduced 14CO2 values were found in 21 of the 22 cirrhotic patients and seven of those had noncirrhotic liver disease associated with severe functional reserve impairment. The values in patients with minor liver diseases or cholestasis were normal. In the cirrhotic patients 2 hr.-(C14)-aminopyrine breath test scores correlated with prothrombin time, retention of bromosulfalein, fasting serum bile acid, albumin, bilirubin, serum aspartate aminotransferase and, above all, with the scores of the two clinical rating systems. The 2 hr.-(C14)-aminopyrine breath test was superior to conventional tests in quantifying the degree of hepatic functional reserve and forecasting the prognosis.

  20. Biosynthesis of D-xylulose 5-phosphate from D-xylose and polyphosphate through a minimized two-enzyme cascade.

    PubMed

    Kim, Jae-Eung; Zhang, Y-H Percival

    2016-02-01

    Sugar phosphates cannot be produced easily by microbial fermentation because negatively-charged compounds cannot be secreted across intact cell membrane. D-xylulose 5-phosphate (Xu5P), a very expensive sugar phosphate, was synthesized from D-xylose and polyphosphate catalyzed by enzyme cascades in one pot. The synthetic enzymatic pathway comprised of xylose isomerase and xylulokinase was designed to produce Xu5P, along with a third enzyme, polyphosphate kinase, responsible for in site ATP regeneration. Due to the promiscuous activity of the ATP-based xylulokinase from a hyperthermophilic bacterium Thermotoga maritima on polyphosphate, the number of enzymes in the pathway was minimized to two without polyphosphate kinase. The reactions catalyzed by the two-enzyme and three-enzyme pathways were compared for Xu5P production, and the reaction conditions were optimized by examining effects of reaction temperature, enzyme ratio and substrate concentration. The optimized two-enzyme system produced 32 mM Xu5P from 50 mM xylose and polyphosphate after 36 h at 45°C. Biosynthesis of less costly Xu5P from D-xylose and polyphosphate could be highly feasible via this minimized two-enzyme pathway.

  1. ( sup 14 C)urea breath test for diagnosis of Helicobacter pylori

    SciTech Connect

    Ormand, J.E.; Talley, N.J.; Carpenter, H.A.; Shorter, R.G.; Conley, C.R.; Wilson, W.R.; DiMagno, E.P.; Zinsmeister, A.R.; Phillips, S.F. )

    1990-07-01

    H. pylori is a potent urease producer, a characteristic that has been exploited in the development of the (14C)- and (13C)urea breath tests. The prevalence of H. pylori infection also is known to increase with advancing age; however, the individual patient's age has not routinely been considered when interpreting urea breath test results. The aim of this study was to validate a short, age-adjusted (14C)urea breath test for use in diagnosing H. pylori infections. Forty-one subjects (28 volunteers, 13 patients) underwent esophagogastroduodenoscopy with biopsies. Subjects were defined as being H. pylori-positive if histology or culture was positive. In addition, all subjects completed a 120-min (14C)urea breath test. A logistic regression analysis adjusting for age was used to estimate the probability of H. pylori positivity as a function of the 14C values generated. Sixteen subjects were H. pylori-positive, and 25 were H. pylori-negative. The 14C values generated between 15 and 80 min were found to be equally predictive in identifying H. pylori-positive subjects. Advancing age was associated with a higher probability of H. pylori-positivity. By taking advantage of the statistical probabilities, older patients could be accurately diagnosed with H. pylori at lower 14C values. We found that (14C)urea breath test to be both a sensitive and specific test that can be abbreviated to a 30-min examination (total test time). Moreover, our mathematical model indicates that a patient's age should be considered in order to optimize interpretation of the (14C)urea breath test, although further observations are needed to confirm this model.

  2. Photoacoustic sensor for VOCs: first step towards a lung cancer breath test

    NASA Astrophysics Data System (ADS)

    Wolff, Marcus; Groninga, Hinrich G.; Dressler, Matthias; Harde, Hermann

    2005-08-01

    Development of new optical sensor technologies has a major impact on the progression of diagnostic methods. Specifically, the optical analysis of breath is an extraordinarily promising technique. Spectroscopic sensors for the non-invasive 13C-breath tests (the Urea Breath Test for detection of Helicobacter pylori is most prominent) are meanwhile well established. However, recent research and development go beyond gastroenterological applications. Sensitive and selective detection of certain volatile organic compounds (VOCs) in a patient's breath, could enable the diagnosis of diseases that are very difficult to diagnose with contemporary techniques. For instance, an appropriate VOC biomarker for early-stage bronchial carcinoma (lung cancer) is n-butane (C4H10). We present a new optical detection scheme for VOCs that employs an especially compact and simple set-up based on photoacoustic spectroscopy (PAS). This method makes use of the transformation of absorbed modulated radiation into a sound wave. Employing a wavelength-modulated distributed feedback (DFB) diode laser and taking advantage of acoustical resonances of the sample cell, we performed very sensitive and selective measurements on butane. A detection limit for butane in air in the ppb range was achieved. In subsequent research the sensitivity will be successively improved to match the requirements of the medical application. Upon optimization, our photoacoustic sensor has the potential to enable future breath tests for early-stage lung cancer diagnostics.

  3. Carbon monoxide in exhaled breath testing and therapeutics.

    PubMed

    Ryter, Stefan W; Choi, Augustine M K

    2013-03-01

    Carbon monoxide (CO), a low molecular weight gas, is a ubiquitous environmental product of organic combustion, which is also produced endogenously in the body, as the byproduct of heme metabolism. CO binds to hemoglobin, resulting in decreased oxygen delivery to bodily tissues at toxicological concentrations. At physiological concentrations, CO may have endogenous roles as a potential signaling mediator in vascular function and cellular homeostasis. Exhaled CO (eCO), similar to exhaled nitric oxide (eNO), has been evaluated as a candidate breath biomarker of pathophysiological states, including smoking status, and inflammatory diseases of the lung and other organs. eCO values have been evaluated as potential indicators of inflammation in asthma, stable COPD and exacerbations, cystic fibrosis, lung cancer, or during surgery or critical care. The utility of eCO as a marker of inflammation and its potential diagnostic value remain incompletely characterized. Among other candidate 'medicinal gases' with therapeutic potential, (e.g., NO and H2S), CO has been shown to act as an effective anti-inflammatory agent in preclinical animal models of inflammatory disease, acute lung injury, sepsis, ischemia/reperfusion injury and organ graft rejection. Current and future clinical trials will evaluate the clinical applicability of this gas as a biomarker and/or therapeutic in human disease. PMID:23446063

  4. Use of the single-breath method of estimating cardiac output during exercise-stress testing.

    NASA Technical Reports Server (NTRS)

    Buderer, M. C.; Rummel, J. A.; Sawin, C. F.; Mauldin, D. G.

    1973-01-01

    The single-breath cardiac output measurement technique of Kim et al. (1966) has been modified for use in obtaining cardiac output measurements during exercise-stress tests on Apollo astronauts. The modifications involve the use of a respiratory mass spectrometer for data acquisition and a digital computer program for data analysis. The variation of the modified method for triplicate steady-state cardiac output measurements was plus or minus 1 liter/min. The combined physiological and methodological variation seen during a set of three exercise tests on a series of subjects was 1 to 2.5 liter/min. Comparison of the modified method with the direct Fick technique showed that although the single-breath values were consistently low, the scatter of data was small and the correlation between the two methods was high. Possible reasons for the low single-breath cardiac output values are discussed.

  5. Compressed air demand-type firefighter's breathing system, volume 1. [design analysis and performance tests

    NASA Technical Reports Server (NTRS)

    Sullivan, J. L.

    1975-01-01

    The commercial availability of lightweight high pressure compressed air vessels has resulted in a lightweight firefighter's breathing apparatus. The improved apparatus, and details of its design and development are described. The apparatus includes a compact harness assembly, a backplate mounted pressure reducer assembly, a lightweight bubble-type facemask with a mask mounted demand breathing regulator. Incorporated in the breathing regulator is exhalation valve, a purge valve and a whistle-type low pressure warning that sounds only during inhalation. The pressure reducer assembly includes two pressure reducers, an automatic transfer valve and a signaling device for the low pressure warning. Twenty systems were fabricated, tested, refined through an alternating development and test sequence, and extensively examined in a field evaluation program. Photographs of the apparatus are included.

  6. FEV manoeuvre induced changes in breath VOC compositions: an unconventional view on lung function tests.

    PubMed

    Sukul, Pritam; Schubert, Jochen K; Oertel, Peter; Kamysek, Svend; Taunk, Khushman; Trefz, Phillip; Miekisch, Wolfram

    2016-01-01

    Breath volatile organic compound (VOC) analysis can open a non-invasive window onto pathological and metabolic processes in the body. Decades of clinical breath-gas analysis have revealed that changes in exhaled VOC concentrations are important rather than disease specific biomarkers. As physiological parameters, such as respiratory rate or cardiac output, have profound effects on exhaled VOCs, here we investigated VOC exhalation under respiratory manoeuvres. Breath VOCs were monitored by means of real-time mass-spectrometry during conventional FEV manoeuvres in 50 healthy humans. Simultaneously, we measured respiratory and hemodynamic parameters noninvasively. Tidal volume and minute ventilation increased by 292 and 171% during the manoeuvre. FEV manoeuvre induced substance specific changes in VOC concentrations. pET-CO2 and alveolar isoprene increased by 6 and 21% during maximum exhalation. Then they decreased by 18 and 37% at forced expiration mirroring cardiac output. Acetone concentrations rose by 4.5% despite increasing minute ventilation. Blood-borne furan and dimethyl-sulphide mimicked isoprene profile. Exogenous acetonitrile, sulphides, and most aliphatic and aromatic VOCs changed minimally. Reliable breath tests must avoid forced breathing. As isoprene exhalations mirrored FEV performances, endogenous VOCs might assure quality of lung function tests. Analysis of exhaled VOC concentrations can provide additional information on physiology of respiration and gas exchange. PMID:27311826

  7. FEV manoeuvre induced changes in breath VOC compositions: an unconventional view on lung function tests

    PubMed Central

    Sukul, Pritam; Schubert, Jochen K.; Oertel, Peter; Kamysek, Svend; Taunk, Khushman; Trefz, Phillip; Miekisch, Wolfram

    2016-01-01

    Breath volatile organic compound (VOC) analysis can open a non-invasive window onto pathological and metabolic processes in the body. Decades of clinical breath-gas analysis have revealed that changes in exhaled VOC concentrations are important rather than disease specific biomarkers. As physiological parameters, such as respiratory rate or cardiac output, have profound effects on exhaled VOCs, here we investigated VOC exhalation under respiratory manoeuvres. Breath VOCs were monitored by means of real-time mass-spectrometry during conventional FEV manoeuvres in 50 healthy humans. Simultaneously, we measured respiratory and hemodynamic parameters noninvasively. Tidal volume and minute ventilation increased by 292 and 171% during the manoeuvre. FEV manoeuvre induced substance specific changes in VOC concentrations. pET-CO2 and alveolar isoprene increased by 6 and 21% during maximum exhalation. Then they decreased by 18 and 37% at forced expiration mirroring cardiac output. Acetone concentrations rose by 4.5% despite increasing minute ventilation. Blood-borne furan and dimethyl-sulphide mimicked isoprene profile. Exogenous acetonitrile, sulphides, and most aliphatic and aromatic VOCs changed minimally. Reliable breath tests must avoid forced breathing. As isoprene exhalations mirrored FEV performances, endogenous VOCs might assure quality of lung function tests. Analysis of exhaled VOC concentrations can provide additional information on physiology of respiration and gas exchange. PMID:27311826

  8. FEV manoeuvre induced changes in breath VOC compositions: an unconventional view on lung function tests

    NASA Astrophysics Data System (ADS)

    Sukul, Pritam; Schubert, Jochen K.; Oertel, Peter; Kamysek, Svend; Taunk, Khushman; Trefz, Phillip; Miekisch, Wolfram

    2016-06-01

    Breath volatile organic compound (VOC) analysis can open a non-invasive window onto pathological and metabolic processes in the body. Decades of clinical breath-gas analysis have revealed that changes in exhaled VOC concentrations are important rather than disease specific biomarkers. As physiological parameters, such as respiratory rate or cardiac output, have profound effects on exhaled VOCs, here we investigated VOC exhalation under respiratory manoeuvres. Breath VOCs were monitored by means of real-time mass-spectrometry during conventional FEV manoeuvres in 50 healthy humans. Simultaneously, we measured respiratory and hemodynamic parameters noninvasively. Tidal volume and minute ventilation increased by 292 and 171% during the manoeuvre. FEV manoeuvre induced substance specific changes in VOC concentrations. pET-CO2 and alveolar isoprene increased by 6 and 21% during maximum exhalation. Then they decreased by 18 and 37% at forced expiration mirroring cardiac output. Acetone concentrations rose by 4.5% despite increasing minute ventilation. Blood-borne furan and dimethyl-sulphide mimicked isoprene profile. Exogenous acetonitrile, sulphides, and most aliphatic and aromatic VOCs changed minimally. Reliable breath tests must avoid forced breathing. As isoprene exhalations mirrored FEV performances, endogenous VOCs might assure quality of lung function tests. Analysis of exhaled VOC concentrations can provide additional information on physiology of respiration and gas exchange.

  9. Microdose 14C-urea breath test in detection of Helicobacter pylori.

    PubMed

    Bielański, W; Konturek, S J; Dobrzańska, M J; Pytko-Polończyk, J; Sito, E; Marshall, B J

    1996-03-01

    Etiologic role for Helicobacter pylori (Hp) seems to be well established in gastric pathology. The high urease activity of Hp can be used to detect this bacterium by non-invasive urea breath tests (UBT). We validated the microdose version of the test in which 37 kBq 14C-urea is given orally in capsule. With the cut off value > 100 DPM as positive, UBT results correlated highly significant with combined results for invasive methods i.e. CLOtest + histology score. The reproducibility of the test was 100%. The results obtained for the breath test performed locally were almost identical with that read at remote laboratory. The data found for fasting and fed states of subjects agreed in 87%. When 14C-urea was confined in the mouth of both Hp positive and Hp negative patients UBT showed the presence of urease activity in the mouth cavity. 14C-urea capsule based breath test is highly reliable, safe, and reproducible for detection of Hp in the stomach. Results can be obtained within 15 min if a scintilation counter is nearby, or breath samples can be mailed to a testing laboratory for analysis.

  10. Significance of hydrogen breath tests in children with suspected carbohydrate malabsorption

    PubMed Central

    2014-01-01

    Background Hydrogen breath tests are noninvasive procedures frequently applied in the diagnostic workup of functional gastrointestinal disorders. Here, we review hydrogen breath test results and the occurrence of lactose, fructose and sorbitol malabsorption in pediatric patients; and determine the significance of the findings and the outcome of patients with carbohydrate malabsorption. Methods We included 206 children (88 male, 118 female, median age 10.7 years, range 3–18 years) with a total of 449 hydrogen breath tests (lactose, n = 161; fructose, n = 142; sorbitol, n = 146) into a retrospective analysis. Apart from test results, we documented symptoms, the therapeutic consequences of the test, the outcome and the overall satisfaction of the patients and families. Results In total, 204 (46%) of all breath tests were positive. Long-term follow-up data could be collected from 118 patients. Of 79 patients (67%) who were put on a diet reduced in lactose, fructose and/or sorbitol, the majority (92%, n = 73) reported the diet to be strict and only 13% (n = 10) had no response to diet. Most families (96%, n = 113) were satisfied by the test and the therapy. There were only 21 tests (5%) with a borderline result because the criteria for a positive result were only partially met. Conclusions Hydrogen breath tests can be helpful in the evaluation of children with gastrointestinal symptoms including functional intestinal disorders. If applied for a variety of carbohydrates but only where indicated, around two-third of all children have positive results. The therapeutic consequences are successfully relieving symptoms in the vast majority of patients. PMID:24575947

  11. Dosimetry and reproducibility of a capsule-based C-14 urea breath test

    SciTech Connect

    Combs, M.J.; Stubbs, J.B.; Buck, D.A. |

    1995-05-01

    The aims of this study were (1) to determine the excretion of the C-14 and associated radiation dose and (2) to examine the reproducibility of a commercial C-14 urea breath test for H.pylori diagnosis. Tests were performed on twenty consenting volunteers (13M, 7F, 24-48 yr). Breath samples containing 1 mmol CO{sub 2} were obtained at 0,5,10,15,20,25,30 min. and 1,2,3,4,5,6,12, 24 hrs following administration of the 37kBq C-14 urea test capsule. A 24 hr urine collection was performed with each voiding collected separately. A repeat breath test was performed 24 hr after the first. H. pylori positive (HP+) was defined as a 15 minute breath sample >=50 dpm. Total urine excretion was obtained directly. Breath excretion was modeled by estimating the area under the excretion curve and using a constant factor of 884 mmol CO{sub 2}/ hr. Urine and breath excretion data in HP+ and H. pylori-negative (HP-) volunteers were pooled and fit to a monoexponential function thus estimating the cumulative urinary excretion of unmetabolized urea. Previously reported biokinetic models of C-14 urea and bicarbonate were used to estimate radiation doses form each compound. Weighted sums were calculated for each dose estimate using each group`s excretion fraction distribution. Both HP+ and HP- volunteers excreted an average of 73% of the C-14 over the first 24 hr. HP+ excretion was evenly divided between breath (34%) and urine (38%). HP-excretion is almost solely by the urinary pathway. The maximum dose for HP= was to the red marrow (0.0033 mGy) and a maximum of 0.0054 mGy to the urinary bladder wall for HP-. There was no difference between 15 inch breath samples on the two days (t-test, p>0.6). The minimum HP+ result at 15 inch was 270 dpm and the maximum HP- result at 15 inch was 18 dpm, indicating great separation between HP+ and HP- results. This study verifies previous dose estimates using C-14 excretion data. The test is sensitive and reproducible with a low radiation dose.

  12. 13C labelled cholesteryl octanoate breath test for assessing pancreatic exocrine insufficiency

    PubMed Central

    Ventrucci, M; Cipolla, A; Ubalducci, G; Roda, A; Roda, E

    1998-01-01

    Background—A non-invasive test for assessment of fat digestion has been developed based on the intraluminal hydrolysis of cholesteryl-[1-13C]octanoate by pancreatic esterase. 
Aims—To determine the diagnostic performance of this breath test in the assessment of exocrine pancreatic function. 
Methods—The test was performed in 20 healthy controls, 22 patients with chronic pancreatic disease (CPD), four with biliopancreatic diversion (BPD), and 32 with non-pancreatic digestive diseases (NPD); results were compared with those of other tubeless tests (faecal chymotrypsin and fluorescein dilaurate test). 
Results—Hourly recoveries of 13CO2 were significantly lower in CPD when compared with healthy controls or NPD. In patients with CPD with mild to moderate insufficiency, the curve of 13CO2 recovery was similar to that of healthy controls, while in those with severe insufficiency it was flat. In three patients with CPD with severe steatorrhoea, a repeat test after pancreatic enzyme supplementation showed a significant rise in 13CO2 recovery. The four BPD patients had low and delayed 13CO2 recovery. Only eight of the 32 patients with NPD had abnormal breath test results. There was a significant correlation between the results of the breath test and those of faecal chymotrypsin, the fluorescein dilaurate test, and faecal fat measurements. For the diagnosis of pancreatic disease using the three hour cumulative 13CO2 recovery test, the sensitivity was 68.2% and specificity 75.0%; values were similar to those of the other two tubeless pancreatic function tests. In seven healthy controls, nine patients with CPD, and nine with NPD a second breath test was performed using Na-[1-13C]octanoate and a pancreatic function index was calculated as the ratio of 13C recovery obtained in the two tests: at three hours this index was abnormal in eight patients with CPD and in three with NPD. 
Conclusion—The cholesteryl-[1-13C]octanoate breath test can be useful for the

  13. Breath tests sustainability in hospital settings: cost analysis and reimbursement in the Italian National Health System.

    PubMed

    Volpe, M; Scaldaferri, F; Ojetti, V; Poscia, A

    2013-01-01

    The high demand of Breath Tests (BT) in many gastroenterological conditions in time of limited resources for health care systems, generates increased interest in cost analysis from the point of view of the delivery of services to better understand how use the money to generate value. This study aims to measure the cost of C13 Urea and other most utilized breath tests in order to describe key aspects of costs and reimbursements looking at the economic sustainability for the hospital. A hospital based cost-analysis of the main breath tests commonly delivery in an ambulatory setting is performed. Mean salary for professional nurses and gastroenterologists, drugs/preparation used and disposable materials, purchase and depreciation of the instrument and the testing time was used to estimate the cost, while reimbursements are based on the 2013 Italian National Health System ambulatory pricelist. Variables that could influence the model are considered in the sensitivity analyses. The mean cost for C13--Urea, Lactulose and Lactose BT are, respectively, Euros 30,59; 45,20 and 30,29. National reimbursement often doesn't cover the cost of the analysis, especially considering the scenario with lower number of exam. On the contrary, in high performance scenario all the reimbursement could cover the cost, except for the C13 Urea BT that is high influenced by the drugs cost. However, consideration about the difference between Italian Regional Health System ambulatory pricelist are done. Our analysis shows that while national reimbursement rates cover the costs of H2 breath testing, they do not cover sufficiently C13 BT, particularly urea breath test. The real economic strength of these non invasive tests should be considered in the overall organization of inpatient and outpatient clinic, accounting for complete diagnostic pathway for each gastrointestinal disease.

  14. Breath tests sustainability in hospital settings: cost analysis and reimbursement in the Italian National Health System.

    PubMed

    Volpe, M; Scaldaferri, F; Ojetti, V; Poscia, A

    2013-01-01

    The high demand of Breath Tests (BT) in many gastroenterological conditions in time of limited resources for health care systems, generates increased interest in cost analysis from the point of view of the delivery of services to better understand how use the money to generate value. This study aims to measure the cost of C13 Urea and other most utilized breath tests in order to describe key aspects of costs and reimbursements looking at the economic sustainability for the hospital. A hospital based cost-analysis of the main breath tests commonly delivery in an ambulatory setting is performed. Mean salary for professional nurses and gastroenterologists, drugs/preparation used and disposable materials, purchase and depreciation of the instrument and the testing time was used to estimate the cost, while reimbursements are based on the 2013 Italian National Health System ambulatory pricelist. Variables that could influence the model are considered in the sensitivity analyses. The mean cost for C13--Urea, Lactulose and Lactose BT are, respectively, Euros 30,59; 45,20 and 30,29. National reimbursement often doesn't cover the cost of the analysis, especially considering the scenario with lower number of exam. On the contrary, in high performance scenario all the reimbursement could cover the cost, except for the C13 Urea BT that is high influenced by the drugs cost. However, consideration about the difference between Italian Regional Health System ambulatory pricelist are done. Our analysis shows that while national reimbursement rates cover the costs of H2 breath testing, they do not cover sufficiently C13 BT, particularly urea breath test. The real economic strength of these non invasive tests should be considered in the overall organization of inpatient and outpatient clinic, accounting for complete diagnostic pathway for each gastrointestinal disease. PMID:24443075

  15. Efficient simultaneous saccharification and fermentation of agricultural residues by Saccharomyces cerevisiae and Candida shehatae. The D-xylose fermenting yeast.

    PubMed

    Palnitkar, S S; Lachke, A H

    1990-11-01

    Simultaneous Saccharification and Fermentation (SSF) experiments were carried out on agricultural residues using culture filtrate of Sclerotium rolfsii, which produces high levels of cellulases and hemicellulases for the saccharification of rice straw and bagasse, and Candida shehatae--the D-xylose fermenting yeast, and Saccharomyces cerevisiae, both separately and in coculture, for fermenting the released sugars. The coculture system showed efficient utilization of hydrolyzed sugars with 30-38% and 10-13% increase in ethanol production as compared to C. shehatae and S. cerevisiae, respectively, when cultivated separately. SSF simulation studies were carried out using standard sugar mixtures of glucose, xylose, and cellobiose. Both organisms could not use cellobiose, whereas glucose was used preferentially. C. shehatae was capable of utilizing xylose in the presence of glucose. PMID:2091527

  16. Inhibition of d-xylose isomerase by polyols: atomic details by joint X-ray/neutron crystallography

    SciTech Connect

    Kovalevsky, Andrey; Hanson, B. Leif; Mason, Sax A.; Forsyth, V. Trevor; Fisher, Zoe; Mustyakimov, Marat; Blakeley, Matthew P.; Keen, David A.; Langan, Paul

    2012-09-01

    A joint X-ray/neutron structure of d-xylose isomerase in complex with the inhibitor sorbitol was determined at room temperature at an acidic pH of 5.9. Protonation of the O5 O atom of the sugar was directly observed in the nuclear density maps. Under acidic conditions sorbitol gains a water-mediated interaction with the enzyme active site, which may explain the increased potency of the inhibitor at low pH. d-Xylose isomerase (XI) converts the aldo-sugars xylose and glucose to their keto analogs xylulose and fructose, but is strongly inhibited by the polyols xylitol and sorbitol, especially at acidic pH. In order to understand the atomic details of polyol binding to the XI active site, a 2.0 Å resolution room-temperature joint X-ray/neutron structure of XI in complex with Ni{sup 2+} cofactors and sorbitol inhibitor at pH 5.9 and a room-temperature X-ray structure of XI containing Mg{sup 2+} ions and xylitol at the physiological pH of 7.7 were obtained. The protonation of oxygen O5 of the inhibitor, which was found to be deprotonated and negatively charged in previous structures of XI complexed with linear glucose and xylulose, was directly observed. The Ni{sup 2+} ions occupying the catalytic metal site (M2) were found at two locations, while Mg{sup 2+} in M2 is very mobile and has a high B factor. Under acidic conditions sorbitol gains a water-mediated interaction that connects its O1 hydroxyl to Asp257. This contact is not found in structures at basic pH. The new interaction that is formed may improve the binding of the inhibitor, providing an explanation for the increased affinity of the polyols for XI at low pH.

  17. 13CO2 breath tests in non-invasive hepatological diagnosis

    PubMed Central

    Musialik, Joanna; Kasicka-Jonderko, Anna; Buschhaus, Magdalena

    2015-01-01

    In liver diagnostics, a simple, non-invasive test with high sensitivity and specificity is permanently being sought in order to assess the degree of liver damage. In addition to liver biopsy, algorithms using blood parameters or elastometry are used in clinical practice. However, these methods do not provide information about the true liver reserve, so the liver breath test seem to be a promising diagnostic tool. The basis of this test depends on the ability of particular hepatocyte enzyme systems to metabolise a tested substance labelled with a stable carbon isotope. The kinetics of 13CO2 elimination with expiratory air then permits quantitative assessment of the functional liver reserve and the degree of organ damage. In this paper the most commonly used tests, grouped according to the main metabolic pathways, are described. The usefulness of liver breath tests in specific clinical situations, both as a diagnostic and prognostic tool, is presented. PMID:25960807

  18. System for routine testing of self-contained and airline breathing equipment

    SciTech Connect

    McDermott, H.J.; Hermens, G.A.

    1980-07-01

    A system for routine testing of self-contained and airline breathing equipment, developed by Shell Oil Co., for testing breathing equipment at one of its refineries, consists of an 80 psig air supply for airline respirators; a 500-2100 psig air supply for self-contained units; a regulator test system which uses a mannequin head that simulates human inhalation and which tests the ability of the regulator to keep the mask interior at the correct positive pressure; and an exhalation valve test system which identifies a leaky or sticking valve. The testing system has been in use for about 30 mo and has led to increased acceptance of respiratory protective equipment by workers.

  19. Assessment of potential causes of falsely positive Mycobacterium tuberculosis breath test.

    PubMed

    Scott-Thomas, Amy; Syhre, Mona; Epton, Michael; Murdoch, David R; Chambers, Stephen T

    2013-05-01

    A suite of volatiles have previously been identified as specific markers of Mycobacterium tuberculosis metabolism in vitro. These markers - methyl phenylacetate, methyl p-anisate, methyl nicotinate, o-phenylanisole with the addition of methyl salicylate, may also be derived from other sources and confound development of a breath test for tuberculosis. To identify potential sources of these potential biomarkers food products, cosmetics, TB medication, environmental air and cigarette smoke were analysed for these markers using solid phase microextraction coupled with Gas Chromatography/Mass Spectrometry. Breath from healthy subjects, including smokers was also tested. Methyl salicylate was commonly detected, making this unsuitable as a specific marker for M. tuberculosis. Methyl nicotinate was detected repeatedly in cigarettes. Methyl phenylacetate was detected in 1.7% of healthy subjects and o-phenylanisole in just 1% of healthy breath indicating these may be more suitable for inclusion in the tuberculosis breath test due to their low "background" level. These results justify further clinical studies to further explore these markers as specific indicators of M. tuberculosis infection.

  20. Evaluation of a [13C]-Dextromethorphan Breath Test to Assess CYP2D6 Phenotype

    PubMed Central

    Leeder, J. Steven; Pearce, Robin E.; Gaedigk, Andrea; Modak, Anil; Rosen, David I.

    2016-01-01

    A [13C]-dextromethorphan ([13C]-DM) breath test was evaluated to assess its feasibility as a rapid, phenotyping assay for CYP2D6 activity. [13C]-DM (0.5 mg/kg) was administered orally with water or potassium bicarbonate-sodium bicarbonate to 30 adult Caucasian volunteers (n = 1 each): CYP2D6 poor metabolizers (2 null alleles; PM-0) and extensive metabolizers with 1 (EM-1) or 2 functional alleles (EM-2). CYP2D6 phenotype was determined by 13CO2 enrichment measured by infrared spectrometry (delta-over-baseline [DOB] value) in expired breath samples collected before and up to 240 minutes after [13C]-DM ingestion and by 4-hour urinary metabolite ratio. The PM-0 group was readily distinguishable from either EM group by both the breath test and urinary metabolite ratio. Using a single point determination of phenotype at 40 minutes and defining PMs as subjects with a DOB ≤ 0.5, the sensitivity of the method was 100%; specificity was 95% with 95% accuracy and resulted in the misclassification of 1 EM-1 individual as a PM. Modification of the initial protocol (timing of potassium bicarbonate-sodium bicarbonate administration relative to dose) yielded comparable results, but there was a tendency toward increased DOB values. Although further development is required, these studies suggest that the [13C]-DM breath test offers promise as a rapid, minimally invasive phenotyping assay for CYP2D6 activity. PMID:18728242

  1. Feasibility of a breath test for monitoring adherence to vaginal administration of antiretroviral microbicide gels.

    PubMed

    Morey, Timothy E; Wasdo, Scott; Wishin, Judith; Quinn, Brian; van der Straten, Ariane; Booth, Matthew; Gonzalez, Daniel; Derendorf, Hartmut; Melker, Richard J; Dennis, Donn M

    2013-01-01

    Adherence to microbicide gel use is critical to optimizing effectiveness in preventing human immunodeficiency virus transmission. The authors hypothesized that ester taggants added to vaginal gels would generate exhaled alcohol and ketone metabolites and provide a "breath test" for vaginal gel use. This 2-arm (vaginal and dermal), randomized, participant-blinded, pilot study tested this hypothesis. On 8 visits, healthy women (n = 8) received intravaginal taggant (2-butyl acetate, 2-pentyl acetate, isopropyl butyrate, or 2-pentyl butyrate; 30 mg) formulated in hydroxyethylcellulose or tenofovir placebo gel. A second group (n = 4) of women received the same formulations administered dermally on the forearm to determine if skin administration might confound the system. Breath samples were collected using bags before and after taggant administration for 1 hour. Samples were measured using a miniature gas chromatograph and/or gas chromatography-mass spectroscopy for ester taggant, alcohol, and ketone concentrations. After vaginal administration, 2-butyl acetate, 2-pentyl acetate, and metabolites were observed in breath, whereas isopropyl butyrate, 2-pentyl butyrate, and metabolites were not. Some women reported self-resolving, mild burning (24/64 visits) with vaginal administration or a "bubblegum" taste (7/64 visits). No taggants or metabolites were detected following dermal application. A "breath test" for adherence to antiretroviral vaginal gel application appears physiologically and technically feasible. PMID:23400750

  2. Synthesis of Differentially Protected myo- and chiro-Inositols from D-Xylose; Stereoselectivity in Intramolecular SmI(2)-Promoted Pinacol Reactions.

    PubMed

    Luchetti, Giovanni; Ding, Kejia; Kornienko, Alexander; d'Alarcao, Marc

    2008-10-01

    Methods for the enantioselective conversion of D-xylose to differentially protected myo-inositol and L-chiro-inositol have been developed. The key transformation is a highly diastereoselective intramolecular SmI(2)-promoted pinacol coupling. The stereoselectivity was extremely dependent on the conditions, suggesting a change in mechanism. Preliminary mechanistic experiments and possible explanations for this behavior are discussed.

  3. Additional Value of CH₄ Measurement in a Combined (13)C/H₂ Lactose Malabsorption Breath Test: A Retrospective Analysis.

    PubMed

    Houben, Els; De Preter, Vicky; Billen, Jaak; Van Ranst, Marc; Verbeke, Kristin

    2015-09-07

    The lactose hydrogen breath test is a commonly used, non-invasive method for the detection of lactose malabsorption and is based on an abnormal increase in breath hydrogen (H₂) excretion after an oral dose of lactose. We use a combined (13)C/H₂ lactose breath test that measures breath (13)CO₂ as a measure of lactose digestion in addition to H₂ and that has a better sensitivity and specificity than the standard test. The present retrospective study evaluated the results of 1051 (13)C/H₂ lactose breath tests to assess the impact on the diagnostic accuracy of measuring breath CH₄ in addition to H₂ and (13)CO₂. Based on the (13)C/H₂ breath test, 314 patients were diagnosed with lactase deficiency, 138 with lactose malabsorption or small bowel bacterial overgrowth (SIBO), and 599 with normal lactose digestion. Additional measurement of CH₄ further improved the accuracy of the test as 16% subjects with normal lactose digestion and no H₂-excretion were found to excrete CH₄. These subjects should have been classified as subjects with lactose malabsorption or SIBO. In conclusion, measuring CH₄-concentrations has an added value to the (13)C/H₂ breath test to identify methanogenic subjects with lactose malabsorption or SIBO.

  4. Additional Value of CH₄ Measurement in a Combined (13)C/H₂ Lactose Malabsorption Breath Test: A Retrospective Analysis.

    PubMed

    Houben, Els; De Preter, Vicky; Billen, Jaak; Van Ranst, Marc; Verbeke, Kristin

    2015-09-01

    The lactose hydrogen breath test is a commonly used, non-invasive method for the detection of lactose malabsorption and is based on an abnormal increase in breath hydrogen (H₂) excretion after an oral dose of lactose. We use a combined (13)C/H₂ lactose breath test that measures breath (13)CO₂ as a measure of lactose digestion in addition to H₂ and that has a better sensitivity and specificity than the standard test. The present retrospective study evaluated the results of 1051 (13)C/H₂ lactose breath tests to assess the impact on the diagnostic accuracy of measuring breath CH₄ in addition to H₂ and (13)CO₂. Based on the (13)C/H₂ breath test, 314 patients were diagnosed with lactase deficiency, 138 with lactose malabsorption or small bowel bacterial overgrowth (SIBO), and 599 with normal lactose digestion. Additional measurement of CH₄ further improved the accuracy of the test as 16% subjects with normal lactose digestion and no H₂-excretion were found to excrete CH₄. These subjects should have been classified as subjects with lactose malabsorption or SIBO. In conclusion, measuring CH₄-concentrations has an added value to the (13)C/H₂ breath test to identify methanogenic subjects with lactose malabsorption or SIBO. PMID:26371034

  5. Transcriptional comparison of the filamentous fungus Neurospora crassa growing on three major monosaccharides D-glucose, D-xylose and L-arabinose

    PubMed Central

    2014-01-01

    Background D-glucose, D-xylose and L-arabinose are the three major monosaccharides in plant cell walls. Complete utilization of all three sugars is still a bottleneck for second-generation cellulolytic bioethanol production, especially for L-arabinose. However, little is known about gene expression profiles during L-arabinose utilization in fungi and a comparison of the genome-wide fungal response to these three major monosaccharides has not yet been reported. Results Using next-generation sequencing technology, we have analyzed the transcriptome of N. crassa grown on L-arabinose versus D-xylose, with D-glucose as the reference. We found that the gene expression profiles on L-arabinose were dramatically different from those on D-xylose. It appears that L-arabinose can rewire the fungal cell metabolic pathway widely and provoke the expression of many kinds of sugar transporters, hemicellulase genes and transcription factors. In contrast, many fewer genes, mainly related to the pentose metabolic pathway, were upregulated on D-xylose. The rewired metabolic response to L-arabinose was significantly different and wider than that under no carbon conditions, although the carbon starvation response was initiated on L-arabinose. Three novel sugar transporters were identified and characterized for their substrates here, including one glucose transporter GLT-1 (NCU01633) and two novel pentose transporters, XAT-1 (NCU01132), XYT-1 (NCU05627). One transcription factor associated with the regulation of hemicellulase genes, HCR-1 (NCU05064) was also characterized in the present study. Conclusions We conducted the first transcriptome analysis of Neurospora crassa grown on L-arabinose and performed a comparative analysis with cells grown on D-xylose and D-glucose, which deepens the understanding of the utilization of L-arabinose and D-xylose in filamentous fungi. The dataset generated by this research will be useful for mining target genes for D-xylose and L-arabinose utilization

  6. A novel breath test to directly measure use of vaginal gel and condoms.

    PubMed

    van der Straten, Ariane; Cheng, Helen; Wasdo, Scott; Montgomery, Liz; Smith-McCune, Karen; Booth, Matthew; Gonzalez, Daniel; Derendorf, Hartmut; Morey, Timothy E; Dennis, Donn M

    2013-07-01

    We assessed the feasibility of a breath test to detect women's single or concurrent use of vaginal products by adding ester taggants to vaginal gel and condom lubricant. Healthy non-pregnant women were enrolled into a two-day cohort (N = 13) and a single-day cohort (N = 12) in San Francisco. Within each cohort, women were randomized (5:1) to tagged or untagged products, and inserted in a clinical setting: 4 mL of tenofovir placebo gel (ten tagged with 15 mg 2-pentyl acetate; three untagged), and an artificial phallus with a lubricated condom (11 tagged with 15 mg 2-butyl acetate; two untagged), on two separate days (two-day cohort) or concurrently (single-day cohort). Using a portable mini-gas chromatograph, the presence/absence of taggants was determined in breath specimens collected prior to, and at timed intervals following product exposure. Demographic, clinical and product use experience data were collected by structured interview. All participants completed all visits and inserted their assigned products. At 5 min post-insertion, the breath test was 100% accurate in identifying insertion of the tagged (or untagged) gel and/or condom. The half-life in breath of the two esters tested was <1 h with large variability between individuals, taggants and cohorts. Overall, among those receiving tagged product, six mild and two moderate product-related AEs were reported. All were transient and resolved spontaneously. Additional sensations included taste in mouth (N = 4) and scent (N = 5). The tagged products were well tolerated. This breath test has the potential to accurately and objectively monitor adherence to vaginal gel and condom used separately or concurrently. PMID:23321948

  7. Oral Adherence Monitoring Using a Breath Test to Supplement Highly Active Antiretroviral Therapy

    PubMed Central

    Morey, Timothy E.; Booth, Matthew; Wasdo, Scott; Wishin, Judith; Quinn, Brian; Gonzalez, Daniel; Derendorf, Hartmut; McGorray, Susan P.; Simoni, Jane; Melker, Richard J.; Dennis, Donn M.

    2012-01-01

    A breath-based adherence system to document ingestion of oral medications (e.g., HAART) was investigated. Specifically, the food additive 2-butanol, which can be easily packaged with a drug, is converted via alcohol dehydrogenase to the volatile metabolite 2-butanone that rapidly appears in breath, indicating adherence. In healthy adults using a portable sensor and GC-MS, the following experiments were performed: yield of 2-butanone in breath following ingestion of 2-butanol, adherence system accuracy, and potential interference of the adherence system by food or misplacement of 2-butanol on the tongue. During feasibility testing, every subject exhaled 2-butanone with 6.6±1.5 min to peak concentrations of 548±235 ppb following ingestion of 2-butanol (40 mg). ROC areas at 5 and 10 min were 0.95 (0.86–1.00) and 3 1.00 (1.00–1.00). Food did not interfere. Tongue application resulted in large concentrations of 2-butanol, but not 2-butanone. A breath test to provide definitive evidence of oral medication adherence appears technically feasible. PMID:23001413

  8. Comparison of the analytical capabilities of the BAC Datamaster and Datamaster DMT forensic breath testing devices.

    PubMed

    Glinn, Michele; Adatsi, Felix; Curtis, Perry

    2011-11-01

    The State of Michigan uses the Datamaster as an evidential breath testing device. The newest version, the DMT, will replace current instruments in the field as they are retired from service. The Michigan State Police conducted comparison studies to test the analytical properties of the new instrument and to evaluate its response to conditions commonly cited in court defenses. The effects of mouth alcohol, objects in the mouth, and radiofrequency interference on paired samples from drinking subjects were assessed on the DMT. The effects of sample duration and chemical interferents were assessed on both instruments, using drinking subjects and wet-bath simulators, respectively. Our testing shows that Datamaster and DMT results are essentially identical; the DMT gave accurate readings as compared with measurements made using simulators containing standard ethanol solutions and that the DMT did not give falsely elevated breath alcohol results from any of the influences tested.

  9. Production of Xylitol from D-Xylose by Overexpression of Xylose Reductase in Osmotolerant Yeast Candida glycerinogenes WL2002-5.

    PubMed

    Zhang, Cheng; Zong, Hong; Zhuge, Bin; Lu, Xinyao; Fang, Huiying; Zhuge, Jian

    2015-07-01

    Efficient bioconversion of D-xylose into various biochemicals is critical for the developing lignocelluloses application. In this study, we compared D-xylose utilization in Candida glycerinogenes WL2002-5 transformants expressing xylose reductase (XYL1) in D-xylose metabolism. C. glycerinogenes WL2002-5 expressing XYL1 from Schefferomyces stipitis can produce xylitol. Xylitol production by the recombinant strains was evaluated using a xylitol fermentation medium with glucose as a co-substrate. As glucose was found to be an insufficient co-substrate, various carbon sources were screened for efficient cofactor regeneration, and glycerol was found to be the best co-substrate. The effects of glycerol on the xylitol production rate by a xylose reductase gene (XYL1)-overexpressed mutant of C. glycerinogenes WL2002-5 were investigated. The XYL1-overexpressed mutant produced xylitol from D-xylose using glycerol as a co-substrate for cell growth and NAD (P) H regeneration: 100 g/L D-xylose was completely converted into xylitol when at least 20 g/L glycerol was used as a co-substrate. XYL1 overexpressed mutant grown on glycerol as co-substrate accumulated 2.1-fold increased xylitol concentration over those cells grown on glucose as co-substrate. XYL1 overexpressed mutant produced xylitol with a volumetric productivity of 0.83 g/L/h, and a xylitol yield of 98 % xylose. Recombinant yeast strains obtained in this study are promising candidates for xylitol production. This is the first report of XYL1 gene overexpression of C. glycerinogenes WL2002-5 for enhancing the efficiency of xylitol production. PMID:26018342

  10. Production of Xylitol from D-Xylose by Overexpression of Xylose Reductase in Osmotolerant Yeast Candida glycerinogenes WL2002-5.

    PubMed

    Zhang, Cheng; Zong, Hong; Zhuge, Bin; Lu, Xinyao; Fang, Huiying; Zhuge, Jian

    2015-07-01

    Efficient bioconversion of D-xylose into various biochemicals is critical for the developing lignocelluloses application. In this study, we compared D-xylose utilization in Candida glycerinogenes WL2002-5 transformants expressing xylose reductase (XYL1) in D-xylose metabolism. C. glycerinogenes WL2002-5 expressing XYL1 from Schefferomyces stipitis can produce xylitol. Xylitol production by the recombinant strains was evaluated using a xylitol fermentation medium with glucose as a co-substrate. As glucose was found to be an insufficient co-substrate, various carbon sources were screened for efficient cofactor regeneration, and glycerol was found to be the best co-substrate. The effects of glycerol on the xylitol production rate by a xylose reductase gene (XYL1)-overexpressed mutant of C. glycerinogenes WL2002-5 were investigated. The XYL1-overexpressed mutant produced xylitol from D-xylose using glycerol as a co-substrate for cell growth and NAD (P) H regeneration: 100 g/L D-xylose was completely converted into xylitol when at least 20 g/L glycerol was used as a co-substrate. XYL1 overexpressed mutant grown on glycerol as co-substrate accumulated 2.1-fold increased xylitol concentration over those cells grown on glucose as co-substrate. XYL1 overexpressed mutant produced xylitol with a volumetric productivity of 0.83 g/L/h, and a xylitol yield of 98 % xylose. Recombinant yeast strains obtained in this study are promising candidates for xylitol production. This is the first report of XYL1 gene overexpression of C. glycerinogenes WL2002-5 for enhancing the efficiency of xylitol production.

  11. Accurate diagnosis of Helicobacter pylori. 13C-urea breath test.

    PubMed

    Graham, D Y; Klein, P D

    2000-12-01

    The preferred schema for management of Helicobacter pylori infection is diagnosis, treatment, and confirmation of cure. The 13C-urea breath test is ideal for active H. pylori infection for those in whom endoscopy is not required (e.g., those in whom cancer is not suspected) because it offers the combination of simplicity, accuracy, reliability, and absence of exposure to radioactivity. New versions of the test also offer increasing simplicity and lower costs. PMID:11190073

  12. [The clinical application of 13C-breath tests in pancreatic diseases].

    PubMed

    Cherniavskiĭ, V V

    2014-11-01

    Maldigestion persists in most patients with chronic pancreatitis (GP). The objective lipase and amylase insufficiency diagnosis is needed to achieve an adequate clinical response to oral pancreatic enzyme substitution therapy. The novel data is presented in the article about the role of 13C-mixed triglyceride and 13C-corn starch breath tests as a tools for exocrine pancreatic insufficiency diagnosis, for evaluating fat and starch malabsorbtion in CP patients. 135 patients were included in the investigation. It has been shown, that 13C-breath tests could be useful tools in clinical practice for CP diagnosis. They are well correlate with fecal elastase-1 level, has high sensitivity and specificity for diagnosis of lipase and amylase deficiency. Tests make it possible to choose the initial pancreatic enzyme dosage and are beneficial during the treatment for pancreatic enzyme dose correction.

  13. [DELAYED RESULTS OF ENZYME REPLACEMENT THERAPY, PRESCRIBED BY RESULTS OF 13C-TRIGLYCERIDE BREATH TEST].

    PubMed

    Chernyavskiy, V V; Gvozdetska, L S

    2015-01-01

    Maldigestion persists in most patients with chronic pancreatitis (CP). The objective lipase and amylase insufficiency diagnosis is needed to achieve an adequate clinical response to oral pancreatic enzyme substitution therapy. The novel data is presented in the article about the role of 13C-mixed triglyceride breath test as a tool for exocrine pancreatic insufficiency diagnosis, for evaluating fat malabsorbtion in CP patients. 135 patients were included in the investigation. Delayed results of enzyme replacement therapy were estimated after 1 and 2 year of surveillance. It has been shown, that partial recovery of exocrine pancreatic function is possible, and replacement therapy leads to patients nutritional status improving. Thus 13C-triglyceride breath test could be useful tool in clinical practice for CP diagnosis. The test make it possible to choose the initial pancreatic enzyme dosage and are beneficial during the treatment for pancreatic enzyme dose correction. PMID:26827447

  14. [DELAYED RESULTS OF ENZYME REPLACEMENT THERAPY, PRESCRIBED BY RESULTS OF 13C-TRIGLYCERIDE BREATH TEST].

    PubMed

    Chernyavskiy, V V; Gvozdetska, L S

    2015-01-01

    Maldigestion persists in most patients with chronic pancreatitis (CP). The objective lipase and amylase insufficiency diagnosis is needed to achieve an adequate clinical response to oral pancreatic enzyme substitution therapy. The novel data is presented in the article about the role of 13C-mixed triglyceride breath test as a tool for exocrine pancreatic insufficiency diagnosis, for evaluating fat malabsorbtion in CP patients. 135 patients were included in the investigation. Delayed results of enzyme replacement therapy were estimated after 1 and 2 year of surveillance. It has been shown, that partial recovery of exocrine pancreatic function is possible, and replacement therapy leads to patients nutritional status improving. Thus 13C-triglyceride breath test could be useful tool in clinical practice for CP diagnosis. The test make it possible to choose the initial pancreatic enzyme dosage and are beneficial during the treatment for pancreatic enzyme dose correction.

  15. When Breathing Interferes with Cognition: Experimental Inspiratory Loading Alters Timed Up-and-Go Test in Normal Humans.

    PubMed

    Nierat, Marie-Cécile; Demiri, Suela; Dupuis-Lozeron, Elise; Allali, Gilles; Morélot-Panzini, Capucine; Similowski, Thomas; Adler, Dan

    2016-01-01

    Human breathing stems from automatic brainstem neural processes. It can also be operated by cortico-subcortical networks, especially when breathing becomes uncomfortable because of external or internal inspiratory loads. How the "irruption of breathing into consciousness" interacts with cognition remains unclear, but a case report in a patient with defective automatic breathing (Ondine's curse syndrome) has shown that there was a cognitive cost of breathing when the respiratory cortical networks were engaged. In a pilot study of putative breathing-cognition interactions, the present study relied on a randomized design to test the hypothesis that experimentally loaded breathing in 28 young healthy subjects would have a negative impact on cognition as tested by "timed up-and-go" test (TUG) and its imagery version (iTUG). Progressive inspiratory threshold loading resulted in slower TUG and iTUG performance. Participants consistently imagined themselves faster than they actually were. However, progressive inspiratory loading slowed iTUG more than TUG, a finding that is unexpected with regard to the known effects of dual tasking on TUG and iTUG (slower TUG but stable iTUG). Insofar as the cortical networks engaged in response to inspiratory loading are also activated during complex locomotor tasks requiring cognitive inputs, we infer that competition for cortical resources may account for the breathing-cognition interference that is evidenced here.

  16. When Breathing Interferes with Cognition: Experimental Inspiratory Loading Alters Timed Up-and-Go Test in Normal Humans

    PubMed Central

    Nierat, Marie-Cécile; Demiri, Suela; Dupuis-Lozeron, Elise; Allali, Gilles; Morélot-Panzini, Capucine; Similowski, Thomas; Adler, Dan

    2016-01-01

    Human breathing stems from automatic brainstem neural processes. It can also be operated by cortico-subcortical networks, especially when breathing becomes uncomfortable because of external or internal inspiratory loads. How the “irruption of breathing into consciousness” interacts with cognition remains unclear, but a case report in a patient with defective automatic breathing (Ondine's curse syndrome) has shown that there was a cognitive cost of breathing when the respiratory cortical networks were engaged. In a pilot study of putative breathing-cognition interactions, the present study relied on a randomized design to test the hypothesis that experimentally loaded breathing in 28 young healthy subjects would have a negative impact on cognition as tested by “timed up-and-go” test (TUG) and its imagery version (iTUG). Progressive inspiratory threshold loading resulted in slower TUG and iTUG performance. Participants consistently imagined themselves faster than they actually were. However, progressive inspiratory loading slowed iTUG more than TUG, a finding that is unexpected with regard to the known effects of dual tasking on TUG and iTUG (slower TUG but stable iTUG). Insofar as the cortical networks engaged in response to inspiratory loading are also activated during complex locomotor tasks requiring cognitive inputs, we infer that competition for cortical resources may account for the breathing-cognition interference that is evidenced here. PMID:26978782

  17. When Breathing Interferes with Cognition: Experimental Inspiratory Loading Alters Timed Up-and-Go Test in Normal Humans.

    PubMed

    Nierat, Marie-Cécile; Demiri, Suela; Dupuis-Lozeron, Elise; Allali, Gilles; Morélot-Panzini, Capucine; Similowski, Thomas; Adler, Dan

    2016-01-01

    Human breathing stems from automatic brainstem neural processes. It can also be operated by cortico-subcortical networks, especially when breathing becomes uncomfortable because of external or internal inspiratory loads. How the "irruption of breathing into consciousness" interacts with cognition remains unclear, but a case report in a patient with defective automatic breathing (Ondine's curse syndrome) has shown that there was a cognitive cost of breathing when the respiratory cortical networks were engaged. In a pilot study of putative breathing-cognition interactions, the present study relied on a randomized design to test the hypothesis that experimentally loaded breathing in 28 young healthy subjects would have a negative impact on cognition as tested by "timed up-and-go" test (TUG) and its imagery version (iTUG). Progressive inspiratory threshold loading resulted in slower TUG and iTUG performance. Participants consistently imagined themselves faster than they actually were. However, progressive inspiratory loading slowed iTUG more than TUG, a finding that is unexpected with regard to the known effects of dual tasking on TUG and iTUG (slower TUG but stable iTUG). Insofar as the cortical networks engaged in response to inspiratory loading are also activated during complex locomotor tasks requiring cognitive inputs, we infer that competition for cortical resources may account for the breathing-cognition interference that is evidenced here. PMID:26978782

  18. Update on diagnostic value of breath test in gastrointestinal and liver diseases.

    PubMed

    Siddiqui, Imran; Ahmed, Sibtain; Abid, Shahab

    2016-08-15

    In the field of gastroenterology, breath tests (BTs) are used intermittently as diagnostic tools that allow indirect, non-invasive and relatively less cumbersome evaluation of several disorders by simply quantifying the appearance in exhaled breath of a metabolite of a specific substrate administered. The aim of this review is to have an insight into the principles, methods of analysis and performance parameters of various hydrogen, methane and carbon BTs which are available for diagnosing gastrointestinal disorders such as Helicobacter pylori infection, small intestinal bacterial overgrowth, and carbohydrate malabsorption. Evaluation of gastric emptying is routinely performed by scintigraphy which is however, difficult to perform and not suitable for children and pregnant women, this review has abridged the 13C-octanoic acid test in comparison to scintigraphy and has emphasized on its working protocol and challenges. A new development such as electronic nose test is also highlighted. Moreover we have also explored the limitations and constraints restraining the wide use of these BT. We conclude that breath testing has an enormous potential to be used as a diagnostic modality. In addition it offers distinct advantages over the traditional invasive methods commonly employed. PMID:27574563

  19. Update on diagnostic value of breath test in gastrointestinal and liver diseases

    PubMed Central

    Siddiqui, Imran; Ahmed, Sibtain; Abid, Shahab

    2016-01-01

    In the field of gastroenterology, breath tests (BTs) are used intermittently as diagnostic tools that allow indirect, non-invasive and relatively less cumbersome evaluation of several disorders by simply quantifying the appearance in exhaled breath of a metabolite of a specific substrate administered. The aim of this review is to have an insight into the principles, methods of analysis and performance parameters of various hydrogen, methane and carbon BTs which are available for diagnosing gastrointestinal disorders such as Helicobacter pylori infection, small intestinal bacterial overgrowth, and carbohydrate malabsorption. Evaluation of gastric emptying is routinely performed by scintigraphy which is however, difficult to perform and not suitable for children and pregnant women, this review has abridged the 13C-octanoic acid test in comparison to scintigraphy and has emphasized on its working protocol and challenges. A new development such as electronic nose test is also highlighted. Moreover we have also explored the limitations and constraints restraining the wide use of these BT. We conclude that breath testing has an enormous potential to be used as a diagnostic modality. In addition it offers distinct advantages over the traditional invasive methods commonly employed. PMID:27574563

  20. A Modified Carbon Monoxide Breath Test for Measuring Erythrocyte Lifespan in Small Animals

    PubMed Central

    Ma, Yong-Jian; Zhang, Hou-De; Ji, Yong-Qiang; Zhu, Guo-Liang; Huang, Jia-Liang; Du, Li-Tao; Cao, Ping; Zang, De-Yue; Du, Ji-Hui; Li, Rong; Wang, Lei

    2016-01-01

    This study was to develop a CO breath test for RBC lifespan estimation of small animals. The ribavirin induced hemolysis rabbit models were placed individually in a closed rebreath cage and air samples were collected for measurement of CO concentration. RBC lifespan was calculated from accumulated CO, blood volume, and hemoglobin concentration data. RBC lifespan was determined in the same animals with the standard biotin-labeling method. RBC lifespan data obtained by the CO breath test method for control (CON, 49.0 ± 5.9 d) rabbits, rabbits given 10 mg/kg·d−1 of ribavirin (RIB10, 31.0 ± 4.0 d), and rabbits given 20 mg/kg·d−1 of ribavirin (RIB20, 25.0 ± 2.9 d) were statistically similar (all p > 0.05) to and linearly correlated (r = 0.96, p < 0.01) with the RBC lifespan data obtained for the same rabbits by the standard biotin-labeling method (CON, 51.0 ± 2.7 d; RIB10, 33.0 ± 1.3 d; and RIB20, 27.0 ± 0.8 d). The CO breath test method takes less than 3 h to complete, whereas the standard method requires at least several weeks. In conclusion, the CO breath test method provides a simple and rapid means of estimating RBC lifespan and is feasible for use with small animal models. PMID:27294128

  1. A Modified Carbon Monoxide Breath Test for Measuring Erythrocyte Lifespan in Small Animals.

    PubMed

    Ma, Yong-Jian; Zhang, Hou-De; Ji, Yong-Qiang; Zhu, Guo-Liang; Huang, Jia-Liang; Du, Li-Tao; Cao, Ping; Zang, De-Yue; Du, Ji-Hui; Li, Rong; Wang, Lei

    2016-01-01

    This study was to develop a CO breath test for RBC lifespan estimation of small animals. The ribavirin induced hemolysis rabbit models were placed individually in a closed rebreath cage and air samples were collected for measurement of CO concentration. RBC lifespan was calculated from accumulated CO, blood volume, and hemoglobin concentration data. RBC lifespan was determined in the same animals with the standard biotin-labeling method. RBC lifespan data obtained by the CO breath test method for control (CON, 49.0 ± 5.9 d) rabbits, rabbits given 10 mg/kg·d(-1) of ribavirin (RIB10, 31.0 ± 4.0 d), and rabbits given 20 mg/kg·d(-1) of ribavirin (RIB20, 25.0 ± 2.9 d) were statistically similar (all p > 0.05) to and linearly correlated (r = 0.96, p < 0.01) with the RBC lifespan data obtained for the same rabbits by the standard biotin-labeling method (CON, 51.0 ± 2.7 d; RIB10, 33.0 ± 1.3 d; and RIB20, 27.0 ± 0.8 d). The CO breath test method takes less than 3 h to complete, whereas the standard method requires at least several weeks. In conclusion, the CO breath test method provides a simple and rapid means of estimating RBC lifespan and is feasible for use with small animal models.

  2. Flight test of multi-pulses vertical laser propulsion in air breathing mode

    NASA Astrophysics Data System (ADS)

    Wen, Ming; Wu, Jie; Wang, Guangyu

    2013-05-01

    The air breathing vertical laser propulsion experiment refers to that in the air breathing mode the light craft under the irradiation of incident laser of vertical direction will turn pulse laser energy into the vertical propulsion thrust of the light craft and continue along the fixed rail upward propulsion flight. It is an important experiment to test the minimum single pulse energy, the optimization degree of light craft structure, and the characteristics of turning the laser energy into the thrust. The experiment is to be conducted dozens of meters in height away the ground generally. The article gives a detailed explanation of the whole process of the air breathing vertical propulsion test, including vertical propulsion light craft design, the connections design, the connections performance test, the frictional resistance detection and the whole process of movement performance test. A vertical propulsion tower was used to conduct the single pulse experiment and multi-pulse performance was predicted with a multiple-pulse thrust measuring system. The impulse coupling coefficient was estimated from fight height. Finally, through the experiments of air breathing vertical laser propulsion, the relation of the movement time and flight height was obtained. In the curve, the mean acceleration of the light craft can arrive to 6m/s2 in the first 20 pulses and the propulsion height can reach 3.5m in 1.12s. After 0.65s, the acceleration of the light craft decreased significantly. The results of the article lay the good foundation for the laser propulsion launch system verification.

  3. A Modified Carbon Monoxide Breath Test for Measuring Erythrocyte Lifespan in Small Animals.

    PubMed

    Ma, Yong-Jian; Zhang, Hou-De; Ji, Yong-Qiang; Zhu, Guo-Liang; Huang, Jia-Liang; Du, Li-Tao; Cao, Ping; Zang, De-Yue; Du, Ji-Hui; Li, Rong; Wang, Lei

    2016-01-01

    This study was to develop a CO breath test for RBC lifespan estimation of small animals. The ribavirin induced hemolysis rabbit models were placed individually in a closed rebreath cage and air samples were collected for measurement of CO concentration. RBC lifespan was calculated from accumulated CO, blood volume, and hemoglobin concentration data. RBC lifespan was determined in the same animals with the standard biotin-labeling method. RBC lifespan data obtained by the CO breath test method for control (CON, 49.0 ± 5.9 d) rabbits, rabbits given 10 mg/kg·d(-1) of ribavirin (RIB10, 31.0 ± 4.0 d), and rabbits given 20 mg/kg·d(-1) of ribavirin (RIB20, 25.0 ± 2.9 d) were statistically similar (all p > 0.05) to and linearly correlated (r = 0.96, p < 0.01) with the RBC lifespan data obtained for the same rabbits by the standard biotin-labeling method (CON, 51.0 ± 2.7 d; RIB10, 33.0 ± 1.3 d; and RIB20, 27.0 ± 0.8 d). The CO breath test method takes less than 3 h to complete, whereas the standard method requires at least several weeks. In conclusion, the CO breath test method provides a simple and rapid means of estimating RBC lifespan and is feasible for use with small animal models. PMID:27294128

  4. An acetone breath analyzer using cavity ringdown spectroscopy: an initial test with human subjects under various situations

    NASA Astrophysics Data System (ADS)

    Wang, Chuji; Surampudi, Anand B.

    2008-10-01

    We have developed a portable breath acetone analyzer using cavity ringdown spectroscopy (CRDS). The instrument was initially tested by measuring the absorbance of breath gases at a single wavelength (266 nm) from 32 human subjects under various conditions. A background subtraction method, implemented to obtain absorbance differences, from which an upper limit of breath acetone concentration was obtained, is described. The upper limits of breath acetone concentration in the four Type 1 diabetes (T1D) subjects, tested after a 14 h overnight fast, range from 0.80 to 3.97 parts per million by volume (ppmv), higher than the mean acetone concentration (0.49 ppmv) in non-diabetic healthy breath reported in the literature. The preliminary results show that the instrument can tell distinctive differences between the breath from individuals who are healthy and those with T1D. On-line monitoring of breath gases in healthy people post-exercise, post-meals and post-alcohol-consumption was also conducted. This exploratory study demonstrates the first CRDS-based acetone breath analyzer and its potential application for point-of-care, non-invasive, diabetic monitoring.

  5. Study the performance of photogalvanic cells for solar energy conversion and storage: Rose Bengal-D-Xylose-NaLS system

    SciTech Connect

    Gangotri, K.M.; Bhimwal, Mahesh Kumar

    2010-07-15

    The Rose Bengal is used as photosensitizer with D-Xylose as reductant and sodium lauryl sulphate (NaLS) as surfactant for the enhancement of the conversion efficiency and storage capacity of photogalvanic cell for its commercial viability. The observed value of the photogeneration of photopotential was 885.0 mV and photocurrent was 460.0 {mu}A whereas maximum power of the cell was 407.10 {mu}W. The observed power at power point was 158.72 {mu}W and the conversion efficiency was 1.52%. The fill factor 0.3151 was experimentally determined at the power point of the cell. The rate of initial generation of photocurrent was 63.88 {mu}A min{sup -1}. The photogalvanic cell so developed can work for 145.0 min in dark on irradiation for 165.0 min, i.e. the storage capacity of the photogalvanic cell is 87.87%. A simple mechanism for the photogeneration of photocurrent has also been proposed. (author)

  6. Taxonomy and physiological characterisation of Scheffersomyces titanus sp. nov., a new D-xylose-fermenting yeast species from China

    PubMed Central

    Liu, Xiao-Jing; Cao, Wan-Nan; Ren, Yong-Cheng; Xu, Long-Long; Yi, Ze-Hao; Liu, Zheng; Hui, Feng-Li

    2016-01-01

    Three strains of a d-xylose-fermenting yeast species were isolated from the host beetle Dorcus titanus collected from two different localities in Henan Province, Central China. These strains formed two hat-shaped ascospores in conjugated and deliquescent asci. Multilocus phylogenetic analysis that included the nearly complete small subunit (SSU), the internal transcribed spacer (ITS) region and the D1/D2 domains of the large subunit (LSU) rDNAs, as well as RNA polymerase II largest subunit (RPB1) gene demonstrated that these strains represent a novel yeast species belonging to the genus Scheffersomyces. The phylogenetic analysis based on the nucleotide sequences of the xylose reductase (XYL1) gene supported the view that the new strains could be grouped as a unique species. Although this new species is highly similar to Scheffersomyces stipitis-like yeasts in terms of nrDNA sequences and morphological and physiological characteristics, the species can be clearly differentiated from its close relatives on the basis of the sequences of XYL1 and RPB1. Therefore, a novel yeast species, Scheffersomyces titanus sp. nov., is proposed to accommodate these strains. The type strain is NYNU 14712T (CICC 33061T = CBS 13926T). PMID:27558134

  7. Description of Scheffersomyces henanensis sp. nov., a New D-Xylose-Fermenting Yeast Species Isolated from Rotten Wood

    PubMed Central

    Ren, Yongcheng; Chen, Liang; Niu, Qiuhong; Hui, Fengli

    2014-01-01

    Two strains of a D-xylose-fermenting yeast species were isolated from rotten wood samples collected from the Baotianman Nature Reserve in Henan Province, central China. These strains formed hat-shaped ascospores in conjugated and deliquescent asci. Multilocus phylogenetic analysis that included the nearly complete small subunit (SSU), the internal transcribed spacer (ITS) region and the D1/D2 domain of the large subunit (LSU) rRNA genes, as well as RNA polymerase II largest subunit (RPB1) gene demonstrated that the two strains represent a novel yeast species closely related to Scheffersomyces segobiensis. A sequence comparison of xylose reductase (XYL1) gene, which was recently recommended for rapid identification of cryptic species in the Scheffersomyces clade, revealed a significant sequence divergence of 25 nucleotides between the novel strains and their closest relative S. segobiensis, supporting their classification as a distinct species. Furthermore, these new strains can be clearly distinguished from S. segobiensis by a number of morphological and physiological characteristics. Therefore, a novel yeast species, Scheffersomyces henanensis sp. nov., is proposed to accommodate these strains. The type strain is BY-41T ( =  CICC 1974T  =  CBS 12475T). PMID:24647466

  8. Taxonomy and physiological characterisation of Scheffersomyces titanus sp. nov., a new D-xylose-fermenting yeast species from China.

    PubMed

    Liu, Xiao-Jing; Cao, Wan-Nan; Ren, Yong-Cheng; Xu, Long-Long; Yi, Ze-Hao; Liu, Zheng; Hui, Feng-Li

    2016-01-01

    Three strains of a d-xylose-fermenting yeast species were isolated from the host beetle Dorcus titanus collected from two different localities in Henan Province, Central China. These strains formed two hat-shaped ascospores in conjugated and deliquescent asci. Multilocus phylogenetic analysis that included the nearly complete small subunit (SSU), the internal transcribed spacer (ITS) region and the D1/D2 domains of the large subunit (LSU) rDNAs, as well as RNA polymerase II largest subunit (RPB1) gene demonstrated that these strains represent a novel yeast species belonging to the genus Scheffersomyces. The phylogenetic analysis based on the nucleotide sequences of the xylose reductase (XYL1) gene supported the view that the new strains could be grouped as a unique species. Although this new species is highly similar to Scheffersomyces stipitis-like yeasts in terms of nrDNA sequences and morphological and physiological characteristics, the species can be clearly differentiated from its close relatives on the basis of the sequences of XYL1 and RPB1. Therefore, a novel yeast species, Scheffersomyces titanus sp. nov., is proposed to accommodate these strains. The type strain is NYNU 14712(T) (CICC 33061(T) = CBS 13926(T)). PMID:27558134

  9. 13C-urea breath test for diagnosis of experimental Helicobacter pylori infection in barrier born pigs.

    PubMed Central

    Meyer-Rosberg, K; Gustavsson, S

    1993-01-01

    Previous studies with Helicobacter pylori infected barrier born pigs indicate that the infection has a patchy distribution, resulting in false negative culture results on endoscopic biopsy specimens. This study aimed to adapt the 13C-urea breath test as used in humans to diagnose H pylori infection in barrier born pigs. The breath test was also performed after bismuth as a single treatment and after triple therapy (bismuth, ampicillin, metronidazole). In control pigs the median excess of 13CO2 in expired air was 2.2 (range 0-12 n = 22) ppm. The infected pigs (n = 4) showed consistently high values (median 23 range 14-43) when examined on four occasions (n = 16) four to 10 weeks after inoculation. Biopsy specimens for culture had lower sensitivity than the breath test. No reduction in excess 13CO2 was seen after three days' single bismuth treatment, but after two weeks' triple therapy the breath test results had returned to normal. This suppression was temporary only, however, as the breath test was positive again four weeks after stopping treatment. In conclusion, the 13C-urea breath test is a simple and reliable test for determining H pylori infection and monitoring treatment effects in barrier born pigs. Because the test can be performed in awake pigs anaesthesia and gastroscopy are unnecessary. Images Figure 1 PMID:8504957

  10. New Zealand's breath and blood alcohol testing programs: further data analysis and forensic implications.

    PubMed

    Stowell, A R; Gainsford, A R; Gullberg, R G

    2008-07-01

    Paired blood and breath alcohol concentrations (BAC, in g/dL, and BrAC, in g/210 L), were determined for 11,837 drivers apprehended by the New Zealand Police. For each driver, duplicate BAC measurements were made using headspace gas chromatography and duplicate BrAC measurements were made with either Intoxilyzer 5000, Seres 679T or Seres 679ENZ Ethylometre infrared analysers. The variability of differences between duplicate results is described in detail, as well as the variability of differences between the paired BrAC and BAC results. The mean delay between breath and blood sampling was 0.73 h, ranging from 0.17 to 3.1 8h. BAC values at the time of breath testing were estimated by adjusting BAC results using an assumed blood alcohol clearance rate. The paired BrAC and time-adjusted BAC results were analysed with the aim of estimating the proportion of false-positive BrAC results, using the time-adjusted BAC results as references. When BAC results were not time-adjusted, the false-positive rate (BrAC>BAC) was 31.3% but after time-adjustment using 0.019 g/dL/h as the blood alcohol clearance rate, the false-positive rate was only 2.8%. However, harmful false-positives (defined as cases where BrAC>0.1 g/210L, while BAC< or =0.1g/dL) occurred at a rate of only 0.14%. When the lower of duplicate breath test results were used as the evidential results instead of the means, the harmful false-positive rate dropped to 0.04%.

  11. Diagnosing lactose malabsorption in children: difficulties in interpreting hydrogen breath test results.

    PubMed

    Ruzsanyi, Veronika; Heinz-Erian, Peter; Entenmann, Andreas; Karall, Daniela; Müller, Thomas; Schimkowitsch, Alexander; Amann, Anton; Scholl-Bürgi, Sabine

    2016-03-01

    Lactose malabsorption (LM) is caused by insufficient enzymatic degradation of the disaccharide by intestinal lactase. Although hydrogen (H2) breath tests (HBTs) are routinely applied to diagnose LM, false-negative results are not uncommon. Thirty-two pediatric patients (19 females, 13 males) were included in this prospective study. After oral lactose administration (1 g kg(-1) bodyweight to a maximum of 25 g), breath H2 was measured by electrochemical detection. HBT was considered positive if H2 concentration exceeded an increase of  ⩾20 ppm from baseline. In addition to H2, exhaled methane (CH4), blood glucose concentrations and clinical symptoms (flatulence, abdominal pain, diarrhea) were monitored. A positive HBT indicating LM was found in 12/32 (37.5%) patients. Only five (41.7%, 5/12) of these had clinical symptoms during HBT indicating lactose intolerance (LI). Decreased blood glucose concentration increments (⩽20 mg dL(-1) (⩽1.1 mmol L(-1))) were found in 3/5 of these patients. CH4 concentrations  ⩾10 ppm at any time during the test were observed in 5/32 (15.6%) patients and in 9/32 (28.1%) between 1 ppm and 9 ppm above baseline after lactose ingestion. In patients with positive HBT 10/12 (83.3%) showed elevated CH4 (>1 ppm) above baseline in breath gas, whereas in patients with negative HBT this figure was only 4/17 (23.5%). In addition to determining H2 in exhaled air, documentation of clinical symptoms, measurement of blood glucose and breath CH4 concentrations may be helpful in deciding whether in a given case an HBT correctly identifies patients with clinically relevant LM.

  12. Diagnosing lactose malabsorption in children: difficulties in interpreting hydrogen breath test results.

    PubMed

    Ruzsanyi, Veronika; Heinz-Erian, Peter; Entenmann, Andreas; Karall, Daniela; Müller, Thomas; Schimkowitsch, Alexander; Amann, Anton; Scholl-Bürgi, Sabine

    2016-03-01

    Lactose malabsorption (LM) is caused by insufficient enzymatic degradation of the disaccharide by intestinal lactase. Although hydrogen (H2) breath tests (HBTs) are routinely applied to diagnose LM, false-negative results are not uncommon. Thirty-two pediatric patients (19 females, 13 males) were included in this prospective study. After oral lactose administration (1 g kg(-1) bodyweight to a maximum of 25 g), breath H2 was measured by electrochemical detection. HBT was considered positive if H2 concentration exceeded an increase of  ⩾20 ppm from baseline. In addition to H2, exhaled methane (CH4), blood glucose concentrations and clinical symptoms (flatulence, abdominal pain, diarrhea) were monitored. A positive HBT indicating LM was found in 12/32 (37.5%) patients. Only five (41.7%, 5/12) of these had clinical symptoms during HBT indicating lactose intolerance (LI). Decreased blood glucose concentration increments (⩽20 mg dL(-1) (⩽1.1 mmol L(-1))) were found in 3/5 of these patients. CH4 concentrations  ⩾10 ppm at any time during the test were observed in 5/32 (15.6%) patients and in 9/32 (28.1%) between 1 ppm and 9 ppm above baseline after lactose ingestion. In patients with positive HBT 10/12 (83.3%) showed elevated CH4 (>1 ppm) above baseline in breath gas, whereas in patients with negative HBT this figure was only 4/17 (23.5%). In addition to determining H2 in exhaled air, documentation of clinical symptoms, measurement of blood glucose and breath CH4 concentrations may be helpful in deciding whether in a given case an HBT correctly identifies patients with clinically relevant LM. PMID:26934035

  13. Assessment of liver function in dogs using the 13C-galactose breath test.

    PubMed

    Silva, S; Wyse, C A; Goodfellow, M R; Yam, P S; Preston, T; Papasouliotis, K; Hall, E J

    2010-08-01

    The aim of this study was to evaluate the application of the 13C-galactose breath test (13C-GBT) in assessing canine liver function by applying it to a group of healthy dogs, and to a group with clinicopathological evidence of liver dysfunction. Breath samples were collected 30 min before ingestion of 13C-galactose, and then at regular intervals thereafter for 6 h. The proportion of 13CO2/12CO2 in the breath samples was measured by isotope-ratio mass spectrometry. There was no significant difference in recovery of 13CO2 in the diseased group, compared to the healthy controls, but there was considerable inter-subject variation in both groups, possibly due to differences in the rate of gastric emptying, which could preclude detection of alterations in hepatic metabolism of galactose. The results of this study do not support the application of the 13C-GBT for assessment of canine liver function. PMID:19546016

  14. XacR - a novel transcriptional regulator of D-xylose and L-arabinose catabolism in the haloarchaeon Haloferax volcanii.

    PubMed

    Johnsen, Ulrike; Sutter, Jan-Moritz; Schulz, Anne-Christine; Tästensen, Julia-Beate; Schönheit, Peter

    2015-05-01

    The haloarchaeon Haloferax volcanii degrades D-xylose and L-arabinose via oxidative pathways to α-ketoglutarate. The genes involved in these pathways are clustered and were transcriptionally upregulated by both D-xylose and L-arabinose suggesting a common regulator. Adjacent to the gene cluster, a putative IclR-like transcriptional regulator, HVO_B0040, was identified. It is shown that HVO_B0040, designated xacR, encodes an activator of both D-xylose and L-arabinose catabolism: in ΔxacR cells, transcripts of genes involved in pentose catabolism could not be detected; transcript formation could be recovered by complementation, indicating XacR dependent transcriptional activation. Upstream activation promoter regions and nucleotide sequences that were essential for XacR-mediated activation of pentose-specific genes were identified by in vivo deletion and scanning mutagenesis. Besides its activator function XacR acted as repressor of its own synthesis: xacR deletion resulted in an increase of xacR promoter activity. A palindromic sequence was identified at the operator site of xacR promoter, and mutation of this sequence also resulted in an increase and thus derepression of xacR promoter activity. It is concluded that the palindromic sequence represents the binding site of XacR as repressor. This is the first report of a transcriptional regulator of pentose catabolism in the domain of archaea.

  15. Arthrobacter D-xylose isomerase: chemical modification of carboxy groups and protein engineering of pH optimum.

    PubMed Central

    Siddiqui, K S; Loviny-Anderton, T; Rangarajan, M; Hartley, B S

    1993-01-01

    To try to lower the pH optimum, the carboxy groups of Arthrobacter D-xylose isomerase were coupled to glycinamide using a water-soluble carbodi-imide. In conditions that substituted all of the 59 carboxy groups in the denatured monomer, a maximum of 30 groups/monomer reacted in the native enzyme, whether in presence or absence of ligands, and the enzyme remained fully active and tetrameric throughout the coupling reaction. Purification by f.p.l.c. ion-exchange chromatography gave broad symmetrical peaks with increased pI, suggesting that the modified enzymes are essentially homogeneous. However, they are less stable than native enzyme in 8 M urea or on heating ('melting points' of 59 degrees versus 73 degrees C for the apoenzymes and 67 degrees versus 81.5 degrees C for the Mg(2+)-enzymes). Kinetic studies of the D-fructose isomerase activity at 30 degrees C showed that the glycinamidylated enzyme had unaltered activation constant for Mg2+, and Km was also similar to that of the native enzyme at pH 7.3, but increased rapidly at higher pH rather than remaining constant. Vmax. was constant from pH 6.2 to 8.0, suggesting a reduced pKa for His-219, which controls Vmax. in the native enzyme (normally 6.0). Three mutants were constructed by protein engineering with a view to reducing the pH optimum of enzyme activity. Two of these, Glu140-->Lys and Asp189-->Lys, could be detected in crude extracts of Escherichia coli by SDS/PAGE, but could not be purified, whereas mutant Trp136-->Glu was produced as a tetramer in amounts similar to the wild-type enzyme. However, it did not show any enzyme activity and was less stable in 0-9 M urea gradient PAGE. Images Figure 2 Figure 6 PMID:7904154

  16. 49 CFR 40.245 - What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... test using a saliva ASD or a breath tube ASD? 40.245 Section 40.245 Transportation Office of the... a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the saliva... ATF. (b) As the STT or BAT, you must take the following steps when using the breath tube ASD:...

  17. 49 CFR 40.245 - What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... test using a saliva ASD or a breath tube ASD? 40.245 Section 40.245 Transportation Office of the... a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the saliva... ATF. (b) As the STT or BAT, you must take the following steps when using the breath tube ASD:...

  18. 49 CFR 40.245 - What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... test using a saliva ASD or a breath tube ASD? 40.245 Section 40.245 Transportation Office of the... a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the saliva... ATF. (b) As the STT or BAT, you must take the following steps when using the breath tube ASD:...

  19. 49 CFR 40.245 - What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... test using a saliva ASD or a breath tube ASD? 40.245 Section 40.245 Transportation Office of the... a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the saliva... ATF. (b) As the STT or BAT, you must take the following steps when using the breath tube ASD:...

  20. A nanomaterial-based breath test for distinguishing gastric cancer from benign gastric conditions

    PubMed Central

    Xu, Z-q; Broza, Y Y; Ionsecu, R; Tisch, U; Ding, L; Liu, H; Song, Q; Pan, Y-y; Xiong, F-x; Gu, K-s; Sun, G-p; Chen, Z-d; Leja, M; Haick, H

    2013-01-01

    Background: Upper digestive endoscopy with biopsy and histopathological evaluation of the biopsy material is the standard method for diagnosing gastric cancer (GC). However, this procedure may not be widely available for screening in the developing world, whereas in developed countries endoscopy is frequently used without major clinical gain. There is a high demand for a simple and non-invasive test for selecting the individuals at increased risk that should undergo the endoscopic examination. Here, we studied the feasibility of a nanomaterial-based breath test for identifying GC among patients with gastric complaints. Methods: Alveolar exhaled breath samples from 130 patients with gastric complaints (37 GC/32 ulcers / 61 less severe conditions) that underwent endoscopy/biopsy were analyzed using nanomaterial-based sensors. Predictive models were built employing discriminant factor analysis (DFA) pattern recognition, and their stability against possible confounding factors (alcohol/tobacco consumption; Helicobacter pylori) was tested. Classification success was determined (i) using leave-one-out cross-validation and (ii) by randomly blinding 25% of the samples as a validation set. Complementary chemical analysis of the breath samples was performed using gas chromatography coupled with mass spectrometry. Results: Three DFA models were developed that achieved excellent discrimination between the subpopulations: (i) GC vs benign gastric conditions, among all the patients (89% sensitivity; 90% specificity); (ii) early stage GC (I and II) vs late stage (III and IV), among GC patients (89% sensitivity; 94% specificity); and (iii) ulcer vs less severe, among benign conditions (84% sensitivity; 87% specificity). The models were insensitive against the tested confounding factors. Chemical analysis found that five volatile organic compounds (2-propenenitrile, 2-butoxy-ethanol, furfural, 6-methyl-5-hepten-2-one and isoprene) were significantly elevated in patients with GC and

  1. Air-breathing aerospace plane development essential: Hypersonic propulsion flight tests

    NASA Technical Reports Server (NTRS)

    Mehta, Unmeel B.

    1994-01-01

    Hypersonic air-breathing propulsion utilizing scramjets can fundamentally change transatmospheric accelerators for low earth-to-orbit and return transportation. The value and limitations of ground tests, of flight tests, and of computations are presented, and scramjet development requirements are discussed. It is proposed that near full-scale hypersonic propulsion flight tests are essential for developing a prototype hypersonic propulsion system and for developing computational-design technology so that it can be used for designing this system. In order to determine how these objectives should be achieved, some lessons learned from past programs are presented. A conceptual two-stage-to-orbit (TSTO) prototype/experimental aerospace plane is recommended as a means of providing access-to-space and for conducting flight tests. A road map for achieving these objectives is also presented.

  2. Hypersonic propulsion flight tests as essential to air-breathing aerospace plane development

    NASA Technical Reports Server (NTRS)

    Mehta, U.

    1995-01-01

    Hypersonic air-breathing propulsion utilizing scramjets can fundamentally change transatmospheric acclerators for transportation from low Earth orbits (LEOs). The value and limitations of ground tests, of flight tests, and of computations are presented, and scramjet development requirements are discussed. Near-full-scale hypersonic propulsion flight tests are essential for developing a prototype hypersonic propulsion system and for developing computation-design technology that can be used in designing that system. In order to determine how these objectives should be achieved, some lessons learned from past programs are presented. A conceptual two-stage-to-orbit (TSTO) prototype/experimental aerospace plane is recommended as a means of providing access-to-space and for conducting flight tests. A road map for achieving these objectives is also presented.

  3. Specific 13C functional pathways as diagnostic targets in gastroenterology breath-tests: tricks for a correct interpretation.

    PubMed

    Pizzoferrato, M; Del Zompo, F; Mangiola, F; Lopetuso, L R; Petito, V; Cammarota, G; Gasbarrini, A; Scaldaferri, F

    2013-01-01

    Breath tests are non-invasive, non-radioactive, safe, simple and effective tests able to determine significant metabolic alterations due to specific diseases or lack of specific enzymes. Carbon isotope (13)C, the stable-non radioactive isotope of carbon, is the most used substrate in breath testing, in which (13)C/(12)C ratio is measured and expressed as a delta value, a differences between readings and a fixed standard. (13)C/(12)C ratio is measured with isotope ratio mass spectrometry or non-dispersive isotope-selective infrared spectrometer and generally there is a good agreement between these techniques in the isotope ratio estimation. (13)C/(12)C ratio can be expressed as static measurement (like delta over baseline in urea breath test) or as dynamic measurement as percent dose recovery, but more dosages are necessary. (13)C Breath-tests are involved in many fields of interest within gastroenterology, such as detection of Helicobacter pylori infection, study of gastric emptying, assessment of liver and exocrine pancreatic functions, determination of oro-caecal transit time, evaluation of absorption and to a lesser extend detection of bacterial overgrowth. The use of every single test in a clinical setting is vary depending on accuracy and substrate costs. This review is meant to present (13)C the meaning of (13)C/(12)C ratio and static and dynamic measure and, finally, the instruments dedicated to its use in gastroenterology. A brief presentation of (13)C breath tests in gastroenterology is also provided. PMID:24443068

  4. Rapid in vivo detection of isoniazid-sensitive Mycobacterium tuberculosis by breath test

    PubMed Central

    Maiga, Mariama C.; Atudorei, Viorel; Sharp, Zachary D.; Bishai, William R.; Timmins, Graham S.

    2014-01-01

    There is urgent need for rapid, point of care diagnostic tools for tuberculosis (TB) and drug sensitivity. Current methods based on in vitro growth take weeks, while DNA amplification can neither differentiate live from dead organisms nor determine phenotypic drug resistance. Here we show the development and evaluation of a rapid breath test for isoniazid (INH)-sensitive TB based on detection of labeled N2 gas formed specifically from labeled INH by mycobacterial KatG enzyme. In vitro data shows the assay is specific, dependent on mycobacterial abundance, and discriminates between INH-sensitive and resistant (S315T mutant KatG) TB. In vivo, the assay is rapid with maximal detection of 15N2 in exhaled breath of infected rabbits within five to ten minutes. No increase in 15N2 is detected in un-infected animals, and the increases in 15N2 are dependent on infection dose. This test may allow rapid detection of INH-sensitive TB. PMID:25247851

  5. Breath tests with stable isotopes: have they a role in liver transplantation?

    PubMed

    Festi, D; Capodicasa, S; Vestito, A; Mazzella, G; Roda, E; Vitacolonna, E; Petrolati, A; Angelico, M; Colecchia, A

    2004-01-01

    Evaluation of liver function is crucial in the overall management of patients with liver disease. In particular, patients with end-stage liver disease need accurate prognostic indicators to plan liver transplantation, and in this case, to manage their presence in the waiting list. Availability of predictors of clinical outcome is further essential after liver transplant, mainly to correctly diagnose and adequately treat complications, such as acute rejection, drug toxicity, liver dysfunction. Breath tests using labelled substrates selectively metabolized within the liver may represent an accurate diagnostic and prognostic tool in these clinical conditions, possibly with an adjuntive role to the most commonly used prognostic models (Child-Pugh and MELD scores). Promising results have been in fact recently obtained by the use of different substrates (aminopyrine, methacetin, erythromycin, methionine) which explore different metabolic function of the hepatocyte. The usefulness of breath tests has been documented in liver disease patients both before and after liver transplantation, in the early as well as in the late phase.

  6. Reporter Phage and Breath Tests: Emerging Phenotypic Assays for Diagnosing Active Tuberculosis, Antibiotic Resistance, and Treatment Efficacy

    PubMed Central

    Jain, Paras; Thaler, David S.; Maiga, Mamoudou; Timmins, Graham S.; Bishai, William R.; Hatfull, Graham F.; Larsen, Michelle H.; Jacobs, William R.

    2011-01-01

    The rapid and accurate diagnosis of active tuberculosis (TB) and its drug susceptibility remain a challenge. Phenotypic assays allow determination of antibiotic susceptibilities even if sequence data are not available or informative. We review 2 emerging diagnostic approaches, reporter phage and breath tests, both of which assay mycobacterial metabolism. The reporter phage signal, Green fluorescent protein (GFP) or β-galactosidase, indicates transcription and translation inside the recipient bacilli and its attenuation by antibiotics. Different breath tests assay, (1) exhaled antigen 85, (2) mycobacterial urease activity, and (3) detection by trained rats of disease-specific odor in sputum, have also been developed. When compared with culture, reporter phage assays shorten the time for initial diagnosis of drug susceptibility by several days. Both reporter phage and breath tests have promise as early markers to determine the efficacy of treatment. While sputum often remains smear and Mycobacterium tuberculosis DNA positive early in the course of efficacious antituberculous treatment, we predict that both breath and phage tests will rapidly become negative. If this hypothesis proves correct, phage assays and breath tests could become important surrogate markers in early bactericidal activity (EBA) studies of new antibiotics. PMID:21996696

  7. Binding Energy and Catalysis by D-Xylose Isomerase: Kinetic, Product and X-Ray Crystallographic Analysis of Enzyme-Catalyzed Isomerization of (R)-Glyceraldehyde‡, ¶

    PubMed Central

    Toteva, Maria M.; Silvaggi, Nicholas R.; Allen, Karen N.; Richard, John P.

    2011-01-01

    D-Xylose isomerase (XI) and triosephosphate isomerase (TIM) catalyze the aldose-ketose isomerization reactions of D-xylose and D-glyceraldehyde 3-phosphate (DGAP), respectively. D-Glyceraldehyde (DGA) is the triose fragment common to the substrates for XI and TIM. The XI-catalyzed isomerization of DGA to give dihydroxyacetone (DHA) in D2O was monitored by 1H NMR spectroscopy and kcat/Km = 0.034 M−1 s−1 was determined for this isomerization at pD 7.0. This is similar to kcat/Km = 0.017 M−1 s−1 for the TIM-catalyzed carbon deprotonation reaction of DGA in D2O at pD 7.0 [Amyes, T. L.; O’Donoghue, A. C. and Richard J. P. (2001) J. Am. Chem. Soc. 123, 11325–11326]. The much larger activation barrier for XI-catalyzed isomerization of D-xylose (kcat/Km = 490 M−1 s−1) than for the TIM-catalyzed isomerization of DGAP (kcat/Km = 9.6 x 106 M−1 s−1) is due to: (i) The larger barrier to conversion of cyclic D-xylose to the reactive linear sugar (5.4 kcal/mol) than for conversion of DGAP hydrate to the free aldehyde (1.7 kcal/mol). (ii) The smaller intrinsic binding energy [Jencks, W. P. (1975) Adv. Enzymol. Relat. Areas Mol. Biol. 43, 219–410] of the terminal ethylene glycol fragment of D-xylose (9.3 kcal/mol) than of the phosphodianion group of DGAP (ca. 12 kcal/mol). The XI-catalyzed isomerization of DGA in D2O at pD 7.0 gives a 90% yield of [1-1H]-DHA and a 10% yield of [1-2H]-DHA, the product of isomerization with deuterium incorporation from solvent D2O. By comparison, the transfer of 3H from labeled hexose substrate to solvent is observed only once in every 109 turnovers for the XI-catalyzed isomerization of [2-3H]-glucose in H2O [Allen, K. N., Lavie, A., Farber, G. K., Glasfeld, A., Petsko, G. A., and Ringe, D. (1994), Biochemistry 33, 1481–1487]. We propose that truncation of the terminal ethylene glycol fragment of D-xylose to give DGA results in a large decrease in the rate of XI-catalyzed isomerization with hydride transfer compared with that

  8. Carbon-14 urea breath test for the diagnosis of Campylobacter pylori associated gastritis

    SciTech Connect

    Marshall, B.J.; Surveyor, I.

    1988-01-01

    Urease in the human gastric mucosa is a marker for infection with Campylobacter pylori (CP), an organism suspected of causing chronic gastritis and peptic ulceration. To detect gastric urease, we examined 32 patients who were being evaluated for possible peptic ulcer disease. Fasting patients were given 10 microCi (370 kBq) of /sup 14/C-labeled urea. Breath samples were collected in hyamine at intervals between 1 and 30 min. The amount of /sup 14/C collected at these times was expressed as: body weight X (% of administered dose of /sup 14/C in sample)/(mmol of CO/sub 2/ collected). The presence of C. pylori colonization was also determined by examination of multiple endoscopic gastric biopsy specimens. On average, patients who were proven to have C. pylori infection exhaled 20 times more labeled CO/sub 2/ than patients who were not infected. The difference between infected patients and C. pylori negative control patients was highly significant at all time points between 2 and 30 min after ingestion of the radionuclide (p less than 0.0001). The noninvasive urea breath is less expensive than endoscopic biopsy of the stomach and more accurate than serology as a means of detecting Campylobacter pylori infection. Because the test detects actual viable CP organisms, it can be used to confirm eradication of the bacterium after antibacterial therapy.

  9. Gravitational independence of single-breath washout tests in recumbent dogs

    NASA Technical Reports Server (NTRS)

    Tomioka, Shinichi; Kubo, Susumu; Guy, Harold J. B.; Prisk, G. K.

    1988-01-01

    The effect of gravitational orientation in the mechanism of lung filling and emptying in dogs was examined by conducting simultaneously Ar-bolus and N2 single-breath washout tests (SBWTs) in 10 anesthetized dogs (prone and supine), with three of the dogs subjected to body rotation. Transpulmonary pressure was measured simultaneously, allowing identification of the lung volume above residual volume at which there was an inflection point in the pressure-volume curve. Combined resident gas and bolus SBWTs in recumbent dogs were found to be different from such tests in humans; in dogs, the regional distribution of ventilation was not primarily determined by gravity. The measurements did not make it possible to discern exact mechanisms of filling and emptying, but both processes appear to be related to lung, thorax, and mediastinum interactions and/or differences in regional mechanical properties of the lungs.

  10. A novel aldose-aldose oxidoreductase for co-production of D-xylonate and xylitol from D-xylose with Saccharomyces cerevisiae.

    PubMed

    Wiebe, Marilyn G; Nygård, Yvonne; Oja, Merja; Andberg, Martina; Ruohonen, Laura; Koivula, Anu; Penttilä, Merja; Toivari, Mervi

    2015-11-01

    An open reading frame CC1225 from the Caulobacter crescentus CB15 genome sequence belongs to the Gfo/Idh/MocA protein family and has 47 % amino acid sequence identity with the glucose-fructose oxidoreductase from Zymomonas mobilis (Zm GFOR). We expressed the ORF CC1225 in the yeast Saccharomyces cerevisiae and used a yeast strain expressing the gene coding for Zm GFOR as a reference. Cell extracts of strains overexpressing CC1225 (renamed as Cc aaor) showed some Zm GFOR type of activity, producing D-gluconate and D-sorbitol when a mixture of D-glucose and D-fructose was used as substrate. However, the activity in Cc aaor expressing strain was >100-fold lower compared to strains expressing Zm gfor. Interestingly, C. crescentus AAOR was clearly more efficient than the Zm GFOR in converting in vitro a single sugar substrate D-xylose (10 mM) to xylitol without an added cofactor, whereas this type of activity was very low with Zm GFOR. Furthermore, when cultured in the presence of D-xylose, the S. cerevisiae strain expressing Cc aaor produced nearly equal concentrations of D-xylonate and xylitol (12.5 g D-xylonate l(-1) and 11.5 g D-xylitol l(-1) from 26 g D-xylose l(-1)), whereas the control strain and strain expressing Zm gfor produced only D-xylitol (5 g l(-1)). Deletion of the gene encoding the major aldose reductase, Gre3p, did not affect xylitol production in the strain expressing Cc aaor, but decreased xylitol production in the strain expressing Zm gfor. In addition, expression of Cc aaor together with the D-xylonolactone lactonase encoding the gene xylC from C. crescentus slightly increased the final concentration and initial volumetric production rate of both D-xylonate and D-xylitol. These results suggest that C. crescentus AAOR is a novel type of oxidoreductase able to convert the single aldose substrate D-xylose to both its oxidized and reduced product.

  11. Novel transporters from Kluyveromyces marxianus and Pichia guilliermondii expressed in Saccharomyces cerevisiae enable growth on L-arabinose and D-xylose.

    PubMed

    Knoshaug, Eric P; Vidgren, Virve; Magalhães, Frederico; Jarvis, Eric E; Franden, Mary Ann; Zhang, Min; Singh, Arjun

    2015-10-01

    Genes encoding L-arabinose transporters in Kluyveromyces marxianus and Pichia guilliermondii were identified by functional complementation of Saccharomyces cerevisiae whose growth on L-arabinose was dependent on a functioning L-arabinose transporter, or by screening a differential display library, respectively. These transporters also transport D-xylose and were designated KmAXT1 (arabinose-xylose transporter) and PgAXT1, respectively. Transport assays using L-arabinose showed that KmAxt1p has K(m) 263 mM and V(max) 57 nM/mg/min, and PgAxt1p has K(m) 0.13 mM and V(max) 18 nM/mg/min. Glucose, galactose and xylose significantly inhibit L-arabinose transport by both transporters. Transport assays using D-xylose showed that KmAxt1p has K(m) 27 mM and V(max) 3.8 nM/mg/min, and PgAxt1p has K(m) 65 mM and V(max) 8.7 nM/mg/min. Neither transporter is capable of recovering growth on glucose or galactose in a S. cerevisiae strain deleted for hexose and galactose transporters. Transport kinetics of S. cerevisiae Gal2p showed K(m) 371 mM and V(max) 341 nM/mg/min for L-arabinose, and K(m) 25 mM and V(max) 76 nM/mg/min for galactose. Due to the ability of Gal2p and these two newly characterized transporters to transport both L-arabinose and D-xylose, one scenario for the complete usage of biomass-derived pentose sugars would require only the low-affinity, high-throughput transporter Gal2p and one additional high-affinity general pentose transporter, rather than dedicated D-xylose or L-arabinose transporters. Additionally, alignment of these transporters with other characterized pentose transporters provides potential targets for substrate recognition engineering.

  12. Comparison of breath-alcohol screening test results with venous blood alcohol concentration in suspected drunken drivers.

    PubMed

    Kriikku, Pirkko; Wilhelm, Lars; Jenckel, Stefan; Rintatalo, Janne; Hurme, Jukka; Kramer, Jan; Jones, A Wayne; Ojanperä, Ilkka

    2014-06-01

    Hand-held electronic breath-alcohol analyzers are widely used by police authorities in their efforts to detect drunken drivers and to improve road-traffic safety. Over a three month period, the results of roadside breath-alcohol tests of drivers apprehended in Finland were compared with venous blood alcohol concentration (BAC). The mean (median) time between sampling blood and breath was 0.71h (0.58h) with a range from 0 to 6h. Some hand-held instruments gave results as the concentration of alcohol in breath and were converted into BAC assuming a blood-breath alcohol ratio (BBR) of 2260. The mean venous BAC (1.82g/kg) in traffic offenders was higher than the result predicted by the hand-held breath analyzers (1.72g/kg). In 1875 roadside tests, the relationship between venous BAC (x) and BrAC (y) was defined by the regression equation y=0.18+0.85x. The coefficients show both a constant bias (y-intercept 0.18g/kg) and a proportional bias (slope=0.85). The residual standard deviation (SD), an indicator of random variation, was ±0.40g/kg. After BAC results were corrected for the time elapsed between sampling blood and breath, the y-intercept decreased to 0.10g/kg and 0.004g/kg, respectively, when low (0.1g/kg/h) and high (0.25g/kg/h) rates of alcohol elimination were used. The proportional bias of 0.85 shows that the breath-alcohol test result reads lower than the actual BAC by 15% on average. This suggests that the BBR of 2260 used for calibration should be increased by about 15% to give closer agreement between BAC and BrAC. Because of the large random variation (SD±0.40g/kg), there is considerable uncertainty if and when results from the roadside screening test are used to estimate venous BAC. The roadside breath-alcohol screening instruments worked well for the purpose of selecting drivers above the statutory limit of 0.50g/kg.

  13. Cross correlation of heart rate and respiration versus deep breathing. Assessment of new test of cardiac autonomic function in diabetes.

    PubMed

    Bernardi, L; Rossi, M; Soffiantino, F; Marti, G; Ricordi, L; Finardi, G; Fratino, P

    1989-05-01

    Cross correlation is a mathematical function whereby spectral analysis is used to describe the relationship between heart-rate fluctuations (256 R-R intervals) and respiration (simultaneously obtained by pneumotacograph). To assess its usefulness for testing autonomic integrity, cross correlation and deep breathing were compared in 141 diabetic subjects (aged 39 +/- 14 yr) and in 77 control subjects (aged 33 +/- 13 yr). To characterize patients, Valsalva maneuver, 30:15 ratio, tilt, and handgrip tests were performed in 96 of these patients; 23 had two or more abnormal tests (group A), 28 had one (group B), and 45 had none (group C). Sensitivity to parasympathetic withdrawal was compared in 9 control subjects (aged 26 +/- 4 yr) by four sequential 0.01-mg/kg i.v. atropine administrations. Reproducibility was compared in 11 control subjects (aged 25 +/- 2 yr) by repeating the tests four times for 2 consecutive days. Considering all 141 patients, cross correlation and deep breathing were less than 2SD of the mean of control subjects in 64 and 36 subjects, respectively. Considering patients who also performed other tests of autonomic function, cross correlation and deep breathing were less than 2SD of the mean of controls in 42 and 30 subjects, respectively (group A, 20 and 15; group B, 12 and 9; group C, 10 and 6). Cross correlation had better reproducibility than deep breathing (C.V. 10.3 vs. 30.6% at 6 breaths/min) and greater sensitivity to atropine (after the 1st injection, cross correlation and deep breathing decreased to 34.6 and 48.2% of baseline values, respectively; P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

  14. (14C)Aminopyrine breath test in chronic liver disease: preliminary diagnostic implications

    SciTech Connect

    Burnstein, A.V.; Galambos, J.T.

    1981-12-01

    The (14C)aminopyrine breath test (APBT) score, an estimate of hepatic mixed-oxidase function, was evaluated in 21 consecutive patients wih active nonalcoholic chronic liver diseases. Ten had primary biliary cirrhosis (PBC) and 11 had chronic active hepatitis (CAH). The APBT score was normal or elevated in patients with PBC (P less than 0.001), and lower than normal in CAH patients (P less than 0.01); 10.5 +/- 1.6 and 3.5 +/- 1.86, respectively, vs control 7.65 +/- 1.15 (mean +/- SD). The 11 patients with CAH included two middle-aged women who displayed ambiguous severe intrahepatic cholestasis. There was no overlap between the APBT scores of the 10 PBC and 11 CAH patients. These initial data suggest that the APBT may be helpful in the differentiation of PBC and CAH, including misleading cholestatic forms of CAH.

  15. 49 CFR 40.245 - What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... test using a saliva ASD or a breath tube ASD? 40.245 Section 40.245 Transportation Office of the... Alcohol Screening Tests § 40.245 What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the...

  16. L-Arabinose binding, isomerization, and epimerization by D-xylose isomerase: X-ray/neutron crystallographic and molecular simulation study.

    PubMed

    Langan, Paul; Sangha, Amandeep K; Wymore, Troy; Parks, Jerry M; Yang, Zamin Koo; Hanson, B Leif; Fisher, Zoe; Mason, Sax A; Blakeley, Matthew P; Forsyth, V Trevor; Glusker, Jenny P; Carrell, Horace L; Smith, Jeremy C; Keen, David A; Graham, David E; Kovalevsky, Andrey

    2014-09-01

    D-xylose isomerase (XI) is capable of sugar isomerization and slow conversion of some monosaccharides into their C2-epimers. We present X-ray and neutron crystallographic studies to locate H and D atoms during the respective isomerization and epimerization of L-arabinose to L-ribulose and L-ribose, respectively. Neutron structures in complex with cyclic and linear L-arabinose have demonstrated that the mechanism of ring-opening is the same as for the reaction with D-xylose. Structural evidence and QM/MM calculations show that in the reactive Michaelis complex L-arabinose is distorted to the high-energy (5)S1 conformation; this may explain the apparent high KM for this sugar. MD-FEP simulations indicate that amino acid substitutions in a hydrophobic pocket near C5 of L-arabinose can enhance sugar binding. L-ribulose and L-ribose were found in furanose forms when bound to XI. We propose that these complexes containing Ni(2+) cofactors are Michaelis-like and the isomerization between these two sugars proceeds via a cis-ene-diol mechanism.

  17. Effect of posture on 13C-urea breath test in partial gastrectomy patients

    PubMed Central

    Yin, Shu-Ming; Zhang, Fan; Shi, Dong-Mei; Xiang, Ping; Xiao, Li; Huang, Yi-Qin; Zhang, Gan-Sheng; Bao, Zhi-Jun

    2015-01-01

    AIM: To investigate whether posture affects the accuracy of 13C-urea breath test (13C-UBT) for Helicobacter pylori (H. pylori) detection in partial gastrectomy patients. METHODS: We studied 156 consecutive residual stomach patients, including 76 with H. pylori infection (infection group) and 80 without H. pylori infection (control group). H. pylori infection was confirmed if both the rapid urease test and histology were positive during gastroscopy. The two groups were divided into four subgroups according to patients’ posture during the 13C-UBT: subgroup A, sitting position; subgroup B, supine position; subgroup C, right lateral recumbent position; and subgroup D, left lateral recumbent position. Each subject underwent the following modified 13C-UBT: 75 mg of 13C-urea (powder) in 100 mL of citric acid solution was administered, and a mouth wash was performed immediately; breath samples were then collected at baseline and at 5-min intervals up to 30 min while the position was maintained. Seven breath samples were collected for each subject. The cutoff value was 2.0‰. RESULTS: The mean delta over baseline (DOB) values in the subgroups of the infection group were similar at 5 min (P > 0.05) and significantly higher than those in the corresponding control subgroups at all time points (P < 0.01). In the infection group, the mean DOB values in subgroup A were higher than those in other subgroups within 10 min and peaked at the 10-min point (12.4‰ ± 2.4‰). The values in subgroups B and C both reached their peaks at 15 min (B, 13.9‰ ± 1.5‰; C, 12.2‰ ± 1.7‰) and then decreased gradually until the 30-min point. In subgroup D, the value peaked at 20 min (14.7‰ ± 1.7‰). Significant differences were found between the values in subgroups D and B at both 25 min (t = 2.093, P = 0.043) and 30 min (t = 2.141, P = 0.039). At 30 min, the value in subgroup D was also significantly different from those in subgroups A and C (D vs C: t = 6.325, P = 0.000; D vs A: t

  18. Employing components-of-variance to evaluate forensic breath test instruments.

    PubMed

    Gullberg, Rod G

    2008-03-01

    The evaluation of breath alcohol instruments for forensic suitability generally includes the assessment of accuracy, precision, linearity, blood/breath comparisons, etc. Although relevant and important, these methods fail to evaluate other important analytical and biological components related to measurement variability. An experimental design comparing different instruments measuring replicate breath samples from several subjects is presented here. Three volunteers provided n = 10 breath samples into each of six different instruments within an 18 minute time period. Two-way analysis of variance was employed which quantified the between-instrument effect and the subject/instrument interaction. Variance contributions were also determined for the analytical and biological components. Significant between-instrument and subject/instrument interaction were observed. The biological component of total variance ranged from 56% to 98% among all subject instrument combinations. Such a design can help quantify the influence of and optimize breath sampling parameters that will reduce total measurement variability and enhance overall forensic confidence.

  19. 13C-breath tests for sucrose digestion in congenital sucrase isomaltase-deficient and sacrosidase-supplemented patients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Congenital sucrase-isomaltase deficiency (CSID) is characterized by absence or deficiency of the mucosal sucrase-isomaltase enzyme. Specific diagnosis requires upper gastrointestinal biopsy with evidence of low to absent sucrase enzyme activity and normal histology. The hydrogen breath test (BT) is ...

  20. Determining the limits and confounders for the 2-pentyl furan breath test by gas chromatography/mass spectrometry.

    PubMed

    Bhandari, Shrawan; Chambers, Stephen; Pearson, John; Syhre, Mona; Epton, Michael; Scott-Thomas, Amy

    2011-09-15

    Aspergillus fumigatus produces 2-pentyl furan (2-PF), a volatile compound not produced by many other pathogens or normal human metabolism. 2-Pentyl furan has been detected in the breath of patients with invasive aspergillosis (IA) by SPME pre-concentration coupled with CG/MS providing the possibility of an attractive diagnostic test. The limit of detection (LOD) and quantification (LOQ) for peak integration were assessed both statistically and empirically respectively. 2-Pentyl furan was detected from 10 of 45 food stuffs tested. Levels were highest from soymilk (3 of 3 brands), lower from pumpkin, peanuts, rolled oats 2, Ensure Plus, tinned asparagus, tinned beans and a vegetable exact (Marmite). No 2-PF was detectable in anti-fungal medications used to treat IA or commonly used cosmetics tested. There was no difference in 2-PF breath levels between morning and afternoon or fasting and non fasting samples taken from healthy subjects eating a diet without 2-PF rich foods. 2-Pentyl furan levels were present in breath samples immediately after a mouth rinse with soy milk (P<0.001), and in some subjects after ingesting soy milk and rinsing their mouth with water. The breath test for 2-PF can be conducted without an overnight fast or at a specified time provided the mouth has been rinsed 30 min or more from when 2-PF containing products have been ingested. PMID:21880557

  1. Impact of hydrogen breath testing on diagnosis, management, and clinical outcome in children with chronic functional GI symptoms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chronic functional gastrointestinal (GI) symptoms (e.g. abdominal pain) in children may have numerous etiologies including carbohydrate malabsorption and small bowel bacterial overgrowth (SBBO). Hydrogen breath testing (HBT) frequently is used as a modality to evaluate for these two diagnoses. Howev...

  2. Bad Breath

    MedlinePlus

    ... habits, like brushing and flossing regularly, help fight bad breath. Mouthwashes, mints or chewing gum may make your breath fresher. If you have an underlying disorder, treating it may help eliminate the breath odor.

  3. Solubility testing of actinides on breathing-zone and area air samples

    SciTech Connect

    Metzger, R.L.; Jessop, B.H.; McDowell, B.L.

    1996-02-01

    A solubility testing method for several common actinides has been developed with sufficient sensitivity to allow profiles to be determined from routine breathing zone and area air samples in the workplace. Air samples are covered with a clean filter to form a filter-sample-filter sandwich which is immersed in an extracellular lung serum simulant solution. The sample is moved to a fresh beaker of the lung fluid simulant each day for one week, and then weekly until the end of the 28 day test period. The soak solutions are wet ashed with nitric acid and hydrogen peroxide to destroy the organic components of the lung simulant solution prior to extraction of the nuclides of interest directly into an extractive scintillator for subsequent counting on a Photon-Electron Rejecting Alpha Liquid Scintillation (PERALS{reg_sign}) spectrometer. Solvent extraction methods utilizing the extractive scintillators have been developed for the isotopes of uranium, plutonium, and curium. The procedures normally produce an isotopic recovery greater than 95% and have been used to develop solubility profiles from air samples with 40 pCi or less of U{sub 3}O{sub 8}. Profiles developed for U{sub 3}O{sub 8} samples show good agreement with in vitro and in vivo tests performed by other investigators on samples from the same uranium mills.

  4. 13C-methacetin breath test correlates with clinical indices of liver disease severity in patients with primary biliary cirrhosis.

    PubMed

    Kochel-Jankowska, A; Hartleb, M; Jonderko, K; Kaminska, M; Kasicka-Jonderko, A

    2013-02-01

    This prospective study intended to ascertain if cytochrome P450 dependent liver function is affected in early and late histological stages of primary biliary cirrhosis (PBC). The study included 32 female PBC patients (mean age 55.4 years, range 33-70) and 16 aged-matched healthy women (mean age 52.6 years, range 38-65). In every subject a 13(C)-methacetin breath test (13(C)-MBT) was applied, and the results were related to histological Ludwig's staging system and several indices of liver disease severity comprising the MAYO-1, MAYO-2, MELD, and Child-Pugh score. The 13(C)-MBT differentiated healthy controls from the patients with Ludwig IV and Ludwig III histopathological stages of PBC. The most significant relationships (i.e. explaining >50% of the variance) were found between measurements of the momentary breath 13(C) elimination from 6 to 18 minutes as well as the 15-min or 30-min cumulative elimination and the MAYO-1 or MAYO-2 scores. The breath test poorly correlated with histopathological features of PBC, however, it accurately discriminated cirrhotic from non-cirrhotic patients (momentary breath 13(C) elimination at 40 min, AUROC 0,958). In conclusion, 13(C)-MBT correlates with clinical scoring systems, especially those specifically designed for PBC (Mayo model) and accurately recognizes the disease at the stage of cirrhosis up to 40 minutes of the test duration.

  5. Additional Value of CH4 Measurement in a Combined 13C/H2 Lactose Malabsorption Breath Test: A Retrospective Analysis

    PubMed Central

    Houben, Els; De Preter, Vicky; Billen, Jaak; Van Ranst, Marc; Verbeke, Kristin

    2015-01-01

    The lactose hydrogen breath test is a commonly used, non-invasive method for the detection of lactose malabsorption and is based on an abnormal increase in breath hydrogen (H2) excretion after an oral dose of lactose. We use a combined 13C/H2 lactose breath test that measures breath 13CO2 as a measure of lactose digestion in addition to H2 and that has a better sensitivity and specificity than the standard test. The present retrospective study evaluated the results of 1051 13C/H2 lactose breath tests to assess the impact on the diagnostic accuracy of measuring breath CH4 in addition to H2 and 13CO2. Based on the 13C/H2 breath test, 314 patients were diagnosed with lactase deficiency, 138 with lactose malabsorption or small bowel bacterial overgrowth (SIBO), and 599 with normal lactose digestion. Additional measurement of CH4 further improved the accuracy of the test as 16% subjects with normal lactose digestion and no H2-excretion were found to excrete CH4. These subjects should have been classified as subjects with lactose malabsorption or SIBO. In conclusion, measuring CH4-concentrations has an added value to the 13C/H2 breath test to identify methanogenic subjects with lactose malabsorption or SIBO. PMID:26371034

  6. l-Arabinose Isomerase and d-Xylose Isomerase from Lactobacillus reuteri: Characterization, Coexpression in the Food Grade Host Lactobacillus plantarum, and Application in the Conversion of d-Galactose and d-Glucose

    PubMed Central

    2014-01-01

    The l-arabinose isomerase (l-AI) and the d-xylose isomerase (d-XI) encoding genes from Lactobacillus reuteri (DSMZ 17509) were cloned and overexpressed in Escherichia coli BL21 (DE3). The proteins were purified to homogeneity by one-step affinity chromatography and characterized biochemically. l-AI displayed maximum activity at 65 °C and pH 6.0, whereas d-XI showed maximum activity at 65 °C and pH 5.0. Both enzymes require divalent metal ions. The genes were also ligated into the inducible lactobacillal expression vectors pSIP409 and pSIP609, the latter containing a food grade auxotrophy marker instead of an antibiotic resistance marker, and the l-AI- and d-XI-encoding sequences/genes were coexpressed in the food grade host Lactobacillus plantarum. The recombinant enzymes were tested for applications in carbohydrate conversion reactions of industrial relevance. The purified l-AI converted d-galactose to d-tagatose with a maximum conversion rate of 35%, and the d-XI isomerized d-glucose to d-fructose with a maximum conversion rate of 48% at 60 °C. PMID:24443973

  7. L-Arabinose isomerase and D-xylose isomerase from Lactobacillus reuteri: characterization, coexpression in the food grade host Lactobacillus plantarum, and application in the conversion of D-galactose and D-glucose.

    PubMed

    Staudigl, Petra; Haltrich, Dietmar; Peterbauer, Clemens K

    2014-02-19

    The L-arabinose isomerase (L-AI) and the D-xylose isomerase (D-XI) encoding genes from Lactobacillus reuteri (DSMZ 17509) were cloned and overexpressed in Escherichia coli BL21 (DE3). The proteins were purified to homogeneity by one-step affinity chromatography and characterized biochemically. L-AI displayed maximum activity at 65 °C and pH 6.0, whereas D-XI showed maximum activity at 65 °C and pH 5.0. Both enzymes require divalent metal ions. The genes were also ligated into the inducible lactobacillal expression vectors pSIP409 and pSIP609, the latter containing a food grade auxotrophy marker instead of an antibiotic resistance marker, and the L-AI- and D-XI-encoding sequences/genes were coexpressed in the food grade host Lactobacillus plantarum . The recombinant enzymes were tested for applications in carbohydrate conversion reactions of industrial relevance. The purified L-AI converted D-galactose to D-tagatose with a maximum conversion rate of 35%, and the D-XI isomerized D-glucose to D-fructose with a maximum conversion rate of 48% at 60 °C.

  8. Breath Tests in Respiratory and Critical Care Medicine: From Research to Practice in Current Perspectives

    PubMed Central

    Cheepsattayakorn, Attapon; Cheepsattayakorn, Ruangrong

    2013-01-01

    Today, exhaled nitric oxide has been studied the most, and most researches have now focusd on asthma. More than a thousand different volatile organic compounds have been observed in low concentrations in normal human breath. Alkanes and methylalkanes, the majority of breath volatile organic compounds, have been increasingly used by physicians as a novel method to diagnose many diseases without discomforts of invasive procedures. None of the individual exhaled volatile organic compound alone is specific for disease. Exhaled breath analysis techniques may be available to diagnose and monitor the diseases in home setting when their sensitivity and specificity are improved in the future. PMID:24151617

  9. Accuracy of urea breath test in Helicobacter pylori infection: Meta-analysis

    PubMed Central

    Ferwana, Mazen; Abdulmajeed, Imad; Alhajiahmed, Ali; Madani, Wedad; Firwana, Belal; Hasan, Rim; Altayar, Osama; Limburg, Paul J; Murad, Mohammad Hassan; Knawy, Bandar

    2015-01-01

    AIM: To quantitatively summarize and appraise the available evidence of urea breath test (UBT) use to diagnose Helicobacter pylori (H. pylori) infection in patients with dyspepsia and provide pooled diagnostic accuracy measures. METHODS: We searched MEDLINE, EMBASE, Cochrane library and other databases for studies addressing the value of UBT in the diagnosis of H. pylori infection. We included cross-sectional studies that evaluated the diagnostic accuracy of UBT in adult patients with dyspeptic symptoms. Risk of bias was assessed using QUADAS (Quality Assessment of Diagnostic Accuracy Studies)-2 tool. Diagnostic accuracy measures were pooled using the random-effects model. Subgroup analysis was conducted by UBT type (13C vs 14C) and by measurement technique (Infrared spectrometry vs Isotope Ratio Mass Spectrometry). RESULTS: Out of 1380 studies identified, only 23 met the eligibility criteria. Fourteen studies (61%) evaluated 13C UBT and 9 studies (39%) evaluated 14C UBT. There was significant variation in the type of reference standard tests used across studies.Pooled sensitivity was 0.96 (95%CI: 0.95-0.97) andpooled specificity was 0.93 (95%CI: 0.91-0.94). Likelihood ratio for a positive test was 12 and for a negative test was 0.05 with an area under thecurve of 0.985. Meta-analyses were associated with a significant statistical heterogeneity that remained unexplained after subgroup analysis. The included studies had a moderate risk of bias. CONCLUSION: UBT has high diagnostic accuracy for detecting H. pylori infection in patients with dyspepsia. The reliability of diagnostic meta-analytic estimates however is limited by significant heterogeneity. PMID:25632206

  10. Gastric emptying rate in subjects with malocclusion examined by [(13) C] breath test.

    PubMed

    Koike, S; Sujino, T; Ohmori, H; Shimazaki, K; Fukuyama, E; Kanai, T; Hibi, T; Ono, T

    2013-08-01

    Masticatory function is significantly lower in individuals with malocclusion than in those with normal occlusion. Although several studies suggest that masticatory function influences gastrointestinal digestive function, the relationship between malocclusion and gastrointestinal symptoms has not been studied extensively. We hypothesised that insufficient masticatory function would increase the functional burden of the stomach and have some influence on the gastrointestinal system. The purpose of this study was to investigate masticatory function and gastric emptying rate in subjects with malocclusion. Eleven healthy dentate female volunteers and eleven female patients with maloc-clusion underwent a (13) C-acetate breath test with a liquid meal. Maximum (13) CO2 exhalation time (Tmax ) was compared statistically between both groups. Masticatory function was assessed by colour-changeable chewing gum. In addition, the frequency scale for the symptoms of gastroeso-phageal reflux disease (FSSG) and questionnaires on food intake were given to both groups. The mean Tmax of the malocclusion group was significantly longer than that of the normal occlusion group (P = 0·007). Masticatory performance, measured by colour-changeable gum and questionnaires, was significantly lower in the malocclusion group than in the normal occlusion group (P = 0·023, P = 0·003). There was no significant difference in the FSSG results between the two groups (P = 0·262). This study suggested that there was a correlation between malocclusion and gastric emptying function in women.

  11. Lactulose Hydrogen Breath Test Result Is Associated with Age and Gender

    PubMed Central

    Newberry, Carolyn; Tierney, Ann; Pickett-Blakely, Octavia

    2016-01-01

    Small intestinal bacterial overgrowth (SIBO) is associated with chronic gastrointestinal diseases and structural/functional abnormalities of the gastrointestinal tract. SIBO's association with clinical characteristics is unclear. This study investigates the association between clinical factors and SIBO according to lactulose hydrogen breath test (LHBT) result. Methods. A cross-sectional study in a university-based gastroenterology practice was performed. Data was abstracted from the medical records of subjects undergoing LHBT from 6/1/2009 to 6/1/2013. Logistic regression analysis was performed to determine the association between predictor variables: age, sex, body mass index (BMI), and positive LHBT, the outcome of interest. Results. LHBT was performed in 791 subjects. Fifty-four percent had a positive LHBT. There was no statistically significant difference between the LHBT results according to age or BMI. In females, the likelihood of a positive LHBT increased with age (OR 1.02; 95% CI: 1.01–1.03). In males, the likelihood of a positive LHBT result decreased with age (OR 0.98; 95% CI: 0.97–1.00). Conclusion. There was an association between age, with respect to sex, and a positive LHBT. With increased age in females, the odds of a positive LHBT increased, while, in men, the odds of a positive LHBT decreased with age. PMID:27073800

  12. Lactulose Hydrogen Breath Test Result Is Associated with Age and Gender.

    PubMed

    Newberry, Carolyn; Tierney, Ann; Pickett-Blakely, Octavia

    2016-01-01

    Small intestinal bacterial overgrowth (SIBO) is associated with chronic gastrointestinal diseases and structural/functional abnormalities of the gastrointestinal tract. SIBO's association with clinical characteristics is unclear. This study investigates the association between clinical factors and SIBO according to lactulose hydrogen breath test (LHBT) result. Methods. A cross-sectional study in a university-based gastroenterology practice was performed. Data was abstracted from the medical records of subjects undergoing LHBT from 6/1/2009 to 6/1/2013. Logistic regression analysis was performed to determine the association between predictor variables: age, sex, body mass index (BMI), and positive LHBT, the outcome of interest. Results. LHBT was performed in 791 subjects. Fifty-four percent had a positive LHBT. There was no statistically significant difference between the LHBT results according to age or BMI. In females, the likelihood of a positive LHBT increased with age (OR 1.02; 95% CI: 1.01-1.03). In males, the likelihood of a positive LHBT result decreased with age (OR 0.98; 95% CI: 0.97-1.00). Conclusion. There was an association between age, with respect to sex, and a positive LHBT. With increased age in females, the odds of a positive LHBT increased, while, in men, the odds of a positive LHBT decreased with age. PMID:27073800

  13. Small Intestinal Bacterial Overgrowth Diagnosed by Glucose Hydrogen Breath Test in Post-cholecystectomy Patients

    PubMed Central

    Sung, Hea Jung; Paik, Chang-Nyol; Chung, Woo Chul; Lee, Kang-Moon; Yang, Jin-Mo; Choi, Myung-Gyu

    2015-01-01

    Background/Aims Patients undergoing cholecystectomy may have small intestinal bacterial overgrowth (SIBO). We investigated the prevalence and characteristics of SIBO in patients with intestinal symptoms following cholecystectomy. Methods Sixty-two patients following cholecystectomy, 145 with functional gastrointestinal diseases (FGIDs), and 30 healthy controls undergoing hydrogen (H2)-methane (CH4) glucose breath test (GBT) were included in the study. Before performing GBT, all patients were interrogated using bowel symptom questionnaire. The positivity to GBT indicating the presence of SIBO, gas types and bowel symptoms were surveyed. Results Post-cholecystectomy patients more often had SIBO as evidenced by a positive (+) GBT than those with FGID and controls (29/62, 46.8% vs 38/145, 26.2% vs 4/30, 13.3%, respectively; P = 0.010). In the gas types, the GBT (H2) + post-cholecystectomy patients was significantly higher than those in FGIDs patients (P = 0.017). Especially, positivity to fasting GBT (H2) among the GBT (H2)+ post-cholecystectomy patients was high, as diagnosed by elevated fasting H2 level. The GBT+ group had higher symptom scores of significance or tendency in abdominal discomfort, bloating, chest discomfort, early satiety, nausea, and tenesmus than those of the GBT negative group. The status of cholecystectomy was the only significant independent factor for predicting SIBO. Conclusions The SIBO with high levels of baseline H2 might be the important etiologic factor of upper GI symptoms for post-cholecystectomy patients. PMID:26351251

  14. Conversion of hemicellulose sugars catalyzed by formic acid: kinetics of the dehydration of D-xylose, L-arabinose, and D-glucose.

    PubMed

    Dussan, Karla; Girisuta, Buana; Lopes, Marystela; Leahy, James J; Hayes, Michael H B

    2015-04-24

    The pre-treatment of lignocellulosic biomass produces a liquid stream of hemicellulose-based sugars, which can be further converted to high-value chemicals. Formosolv pulping and the Milox process use formic acid as the fractionating agent, which can be used as the catalyst for the valorisation of hemicellulose sugars to platform chemicals. The objective of this study was to investigate the reaction kinetics of major components in the hemicelluloses fraction of biomass, that is, D-xylose, L-arabinose and D-glucose. The kinetics experiments for each sugar were performed at temperatures between 130 and 170 °C in various formic acid concentrations (10-64 wt %). The implications of these kinetic models on the selectivity of each sugar to the desired products are discussed. The models were used to predict the reaction kinetics of solutions that resemble the liquid stream obtained from the fractionation process of biomass using formic acid. PMID:25821128

  15. Furfural Production from d-Xylose and Xylan by Using Stable Nafion NR50 and NaCl in a Microwave-Assisted Biphasic Reaction.

    PubMed

    Le Guenic, Sarah; Gergela, David; Ceballos, Claire; Delbecq, Frederic; Len, Christophe

    2016-01-01

    Pentose dehydration and direct transformation of xylan into furfural were performed in a water-cyclopentyl methyl ether (CPME) biphasic system under microwave irradiation. Heated up between 170 and 190 °C in the presence of Nafion NR50 and NaCl, d-xylose, l-arabinose and xylan gave furfural with maximum yields of 80%, 42% and 55%, respectively. The influence of temperature and reaction time on the reaction kinetics was discussed. This study was also completed by the survey of different reactant ratios, such as organic layer-water or catalyst-inorganic salt ratios. The exchange between proton and cation induced by an excess of NaCl was monitored, and a synergetic effect between the remaining protons and the released HCl was also discovered. PMID:27556444

  16. Conversion of hemicellulose sugars catalyzed by formic acid: kinetics of the dehydration of D-xylose, L-arabinose, and D-glucose.

    PubMed

    Dussan, Karla; Girisuta, Buana; Lopes, Marystela; Leahy, James J; Hayes, Michael H B

    2015-04-24

    The pre-treatment of lignocellulosic biomass produces a liquid stream of hemicellulose-based sugars, which can be further converted to high-value chemicals. Formosolv pulping and the Milox process use formic acid as the fractionating agent, which can be used as the catalyst for the valorisation of hemicellulose sugars to platform chemicals. The objective of this study was to investigate the reaction kinetics of major components in the hemicelluloses fraction of biomass, that is, D-xylose, L-arabinose and D-glucose. The kinetics experiments for each sugar were performed at temperatures between 130 and 170 °C in various formic acid concentrations (10-64 wt %). The implications of these kinetic models on the selectivity of each sugar to the desired products are discussed. The models were used to predict the reaction kinetics of solutions that resemble the liquid stream obtained from the fractionation process of biomass using formic acid.

  17. 49 CFR 40.243 - What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD? 40.243 Section 40.243 Transportation Office of the...-evidential breath ASD? As the BAT or STT, you must take the following steps: (a) Select, or allow...

  18. 49 CFR 40.243 - What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD? 40.243 Section 40.243 Transportation Office of the...-evidential breath ASD? As the BAT or STT, you must take the following steps: (a) Select, or allow...

  19. 49 CFR 40.243 - What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD? 40.243 Section 40.243 Transportation Office of the...-evidential breath ASD? As the BAT or STT, you must take the following steps: (a) Select, or allow...

  20. 49 CFR 40.243 - What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD? 40.243 Section 40.243 Transportation Office of the...-evidential breath ASD? As the BAT or STT, you must take the following steps: (a) Select, or allow...

  1. 49 CFR 40.243 - What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 false What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD? 40.243 Section 40.243 Transportation Office of the...-evidential breath ASD? As the BAT or STT, you must take the following steps: (a) Select, or allow...

  2. Man o' War Mutation in UDP-α-D-Xylose Synthase Favors the Abortive Catalytic Cycle and Uncovers a Latent Potential for Hexamer Formation

    SciTech Connect

    Walsh, Jr., Richard M.; Polizzi, Samuel J.; Kadirvelraj, Renuka; Howard, Wesley W.; Wood, Zachary A.

    2015-03-17

    The man o’ war (mow) phenotype in zebrafish is characterized by severe craniofacial defects due to a missense mutation in UDP-α-D-xylose synthase (UXS), an essential enzyme in proteoglycan biosynthesis. The mow mutation is located in the UXS dimer interface ~16 Å away from the active site, suggesting an indirect effect on the enzyme mechanism. We have examined the structural and catalytic consequences of the mow mutation (R236H) in the soluble fragment of human UXS (hUXS), which shares 93% sequence identity with the zebrafish enzyme. In solution, hUXS dimers undergo a concentration-dependent association to form a tetramer. Sedimentation velocity studies show that the R236H substitution induces the formation of a new hexameric species. Using two new crystal structures of the hexamer, we show that R236H and R236A substitutions cause a local unfolding of the active site that allows for a rotation of the dimer interface necessary to form the hexamer. The disordered active sites in the R236H and R236A mutant constructs displace Y231, the essential acid/base catalyst in the UXS reaction mechanism. The loss of Y231 favors an abortive catalytic cycle in which the reaction intermediate, UDP-α-D-4-keto-xylose, is not reduced to the final product, UDP-α-D-xylose. Surprisingly, the mow-induced hexamer is almost identical to the hexamers formed by the deeply divergent UXS homologues from Staphylococcus aureus and Helicobacter pylori (21% and 16% sequence identity, respectively). The persistence of a latent hexamer-building interface in the human enzyme suggests that the ancestral UXS may have been a hexamer.

  3. Assessment of antibacterial effect of garlic in patients infected with Helicobacter pylori using urease breath test

    PubMed Central

    Zardast, Mahmoud; Namakin, Kokab; Esmaelian Kaho, Jamil; Hashemi, Sarira Sadat

    2016-01-01

    Objective: Helicobacter pylori (H. pylori) is the most common pathogenic bacteria in the stomach. The aim of the current study was to explore the effect of oral garlic administration on bacterial urease activity inside the stomach and its contribution to the treatment of H. pylori infection. Materials and Methods: In this clinical trial, 15 patients were studied quantitatively with Urease Breath Test (UBT). The patients with gastrointestinal symptoms and a positive serum H. pylori IgG were enrolled. UBT was performed for each patient in three sessions as follows: at the beginning of the study, an initial UBT was performed based on which, the positive cases entered the study and the negative ones were excluded. Second UBT was done three days later in patients who were not receiving any treatment and were considered as the control, whereas the third UBT was performed three days after prescribing two medium-sized cloves of garlic (3 g) with their meal, twice a day (at noon and in the evening). The collected data were analyzed using ANOVA and Bonferroni tests and the significance level was set at p<0.05. Results: the mean UBT significantly differed before and after treatment with garlic cloves, being significantly lower after garlic consumption. No meaningful difference was observed in the mean UBT without garlic consumption between the first and second steps. Conclusion: Raw garlic has anti-bacterial effects against H. pylori residing in the stomach and may be prescribed along with routine drugs for the treatment of gastric H. pylori infection. PMID:27761418

  4. Utility of wireless motility capsule and lactulose breath testing in the evaluation of patients with chronic functional bloating

    PubMed Central

    Triadafilopoulos, George

    2016-01-01

    Background The precise aetiology of chronic bloating remains poorly understood and underlying gastroparesis, small bowel bacterial overgrowth and colonic inertia may, individually or collectively, play a role. Aims In this retrospective cohort analysis of symptomatic patients with chronic persistent bloating, we determined the clinical utility of wireless motility capsule and lactulose breath test in further defining the underlying aetiology for functional bloating. Methods Consecutive patients with chronic bloating underwent clinical assessment, wireless motility capsule testing and lactulose breath testing using standard protocols. Results 52 patients qualified for inclusion in this analysis, fulfilling Rome III criteria for functional bloating. Most patients (54%) had an abnormal wireless motility capsule study; of those, 11.5% had evidence of gastroparesis, 7.7% had small bowel transit delay, 15.8% had colonic inertia, 3.8% had delayed gastric and small bowel transit, 5.6% had combined gastric and colonic transit delay, 3.8% had delayed small bowel and colonic transit, and 5.6% had delayed gastric, small bowel and colon transit times. Using clinical questionnaires the median scores for bloating, constipation and eructation were not significantly different. Neither constipation nor eructation was specific to gastroparesis or colonic inertia but bloating was numerically more prevalent and severe in patients with delayed small bowel transit. 40% of patients had positive lactulose breath test but had no distinguishing clinical characteristics. Conclusions Chronic functional bloating may reflect underlying gastroparesis, small intestinal bacterial overgrowth or colonic inertia. Wireless motility capsule and lactulose breath test are useful in the assessment of patients with bloating and should be considered during evaluation. PMID:27648298

  5. Utility of wireless motility capsule and lactulose breath testing in the evaluation of patients with chronic functional bloating

    PubMed Central

    Triadafilopoulos, George

    2016-01-01

    Background The precise aetiology of chronic bloating remains poorly understood and underlying gastroparesis, small bowel bacterial overgrowth and colonic inertia may, individually or collectively, play a role. Aims In this retrospective cohort analysis of symptomatic patients with chronic persistent bloating, we determined the clinical utility of wireless motility capsule and lactulose breath test in further defining the underlying aetiology for functional bloating. Methods Consecutive patients with chronic bloating underwent clinical assessment, wireless motility capsule testing and lactulose breath testing using standard protocols. Results 52 patients qualified for inclusion in this analysis, fulfilling Rome III criteria for functional bloating. Most patients (54%) had an abnormal wireless motility capsule study; of those, 11.5% had evidence of gastroparesis, 7.7% had small bowel transit delay, 15.8% had colonic inertia, 3.8% had delayed gastric and small bowel transit, 5.6% had combined gastric and colonic transit delay, 3.8% had delayed small bowel and colonic transit, and 5.6% had delayed gastric, small bowel and colon transit times. Using clinical questionnaires the median scores for bloating, constipation and eructation were not significantly different. Neither constipation nor eructation was specific to gastroparesis or colonic inertia but bloating was numerically more prevalent and severe in patients with delayed small bowel transit. 40% of patients had positive lactulose breath test but had no distinguishing clinical characteristics. Conclusions Chronic functional bloating may reflect underlying gastroparesis, small intestinal bacterial overgrowth or colonic inertia. Wireless motility capsule and lactulose breath test are useful in the assessment of patients with bloating and should be considered during evaluation.

  6. Sensitivity and specificity of an abbreviated 13C-mixed triglyceride breath test for measurement of pancreatic exocrine function

    PubMed Central

    Meier, Viola; Wolfram, Kristina U; Rosien, Ulrich; Layer, Peter

    2014-01-01

    Background A modified 13C-mixed triglyceride breath test (13C -MTGT) detects moderate pancreatic exocrine insufficiency noninvasively and reliably, but it requires prolonged breath sampling (6 hours (hr)). Objective We aimed to investigate whether 13C -MTGT can be abbreviated, to optimize clinical usability. Methods We analyzed the 13C-MTGT of 200 consecutive patients, retrospectively. Cumulative 1–5 hr 13C-exhalation values were compared with the standard parameter (6-hr cumulative 13C-exhalation). We determined the sensitivity and specificity of shortened breath sampling periods, by comparison with the normal values from 10 healthy volunteers, whom also underwent a secretin test to quantitate pancreatic secretion. Moreover, we evaluated the influence of gastric emptying (GE), using a 13C-octanoic acid breath test in a subset (N = 117). Results The 1–5 hr cumulative 13C-exhalation tests correlated highly and significantly with the standard parameter (p < 0.0001). Sensitivity for detection of impaired lipolysis was high (≥77%), but the specificity was low (≥38%) for the early measurements. Both parameters were high after 4 hrs (88% and 94%, respectively) and 5 hrs (98% and 91%, respectively). Multivariate linear correlation analysis confirmed that GE strongly influenced early postprandial 13C-exhalation during the 13C-MTGT. Conclusion Shortening of the 13C -MTGT from 6 to 4 hrs of duration was associated with similar diagnostic accuracy, yet increased clinical usability. The influence of GE on early postprandial results of the 13C-MTGT precluded further abbreviation of the test. PMID:25083286

  7. Validation of a simplified carbon-14-urea breath test for routine use for detecting Helicobacter pylori noninvasively

    SciTech Connect

    Henze, E.; Malfertheiner, P.; Clausen, M.; Burkhardt, H.; Adam, W.E. )

    1990-12-01

    A carbon-14 ({sup 14}C) urea breath test for detecting Helicobacter pylori with multiple breath sampling was developed. Carbon-14-urea (110 kBq) administered orally to 18 normal subjects and to 82 patients with Helicobacter infection. The exhaled {sup 14}C-labeled CO{sub 2} was trapped at 10-min intervals for 90 min. The total {sup 14}C activity exhaled over 90 min was integrated and expressed in %activity of the total dose given. In normals, a mean of 0.59% +/- 0.24% was measured, resulting in an upper limit of normal of 1.07%. In 82 patients, a sensitivity of 90.2%, a specificity of 83.8%, and a positive predictive value of 90.2% was found. The single probes at intervals of 40-60 min correlated best with the integrated result, with r ranging from 0.986 to 0.990. The test's diagnostic accuracy did not change at all when reevaluated with the 40-, 50-, or 60-min sample data alone. Thus, the {sup 14}C-urea breath test can be applied routinely as a noninvasive, low-cost and one-sample test with high diagnostic accuracy in detecting Helicobacter pylori colonization.

  8. Co-immobilization of glucose oxidase and xylose dehydrogenase displayed whole cell on multiwalled carbon nanotube nanocomposite films modified electrode for simultaneous voltammetric detection of D-glucose and D-xylose.

    PubMed

    Li, Liang; Liang, Bo; Li, Feng; Shi, Jianguo; Mascini, Marco; Lang, Qiaolin; Liu, Aihua

    2013-04-15

    In this paper, we first report the construction of Nafion/glucose oxidase (GOD)/xylose dehydrogenase displayed bacteria (XDH-bacteria)/multiwalled carbon nanotubes (MWNTs) modified electrode for simultaneous voltammetric determination of D-glucose and D-xylose. The optimal conditions for the immobilized enzymes were established. Both enzymes retained their good stability and activities. In the mixture solution of D-glucose and D-xylose containing coenzyme NAD⁺ (the oxidized form of nicotinamide adenine dinucleotide), the Nafion/GOD/XDH-bacteria/MWNTs modified electrode exhibited quasi-reversible oxidation-reduction peak at -0.5 V (vs. saturated calomel electrode, SCE) originating from the catalytic oxidation of D-glucose, and oxidation peak at +0.55 V(vs. SCE) responding to the oxidation of NADH (the reduced form of nicotinamide adenine dinucleotide) by the carbon nanotubes, where NADH is the resultant product of coenzyme NAD⁺ involved in the catalysis of D-xylose by XDH-displayed bacteria. For the proposed biosensor, cathodic peak current at -0.5 V was linear with the concentration of D-glucose within the range of 0.25-6 mM with a low detection limit of 0.1 mM D-glucose (S/N=3), and the anodic peak current at +0.55 V was linear with the concentration of d-xylose in the range of 0.25∼4 mM with a low detection limit of 0.1 mM D-xylose (S/N=3). Further, D-xylose and D-glucose did not interfere with each other. 300-fold excess saccharides including D-maltose, D-galactose, D-mannose, D-sucrose, D-fructose, D-cellobiose, and 60-fold excess L-arabinose, and common interfering substances (100-fold excess ascorbic acid, dopamine, uric acid) as well as 300-fold excess D-xylitol did not affect the detection of D-glucose and D-xylose (both 1 mM). Therefore, the proposed biosensor is stable, specific, reproducible, simple, rapid and cost-effective, which holds great potential in real applications. PMID:23202346

  9. Four-sample lactose hydrogen breath test for diagnosis of lactose malabsorption in irritable bowel syndrome patients with diarrhea

    PubMed Central

    Yang, Jian-Feng; Fox, Mark; Chu, Hua; Zheng, Xia; Long, Yan-Qin; Pohl, Daniel; Fried, Michael; Dai, Ning

    2015-01-01

    AIM: To validate 4-sample lactose hydrogen breath testing (4SLHBT) compared to standard 13-sample LHBT in the clinical setting. METHODS: Irritable bowel syndrome patients with diarrhea (IBS-D) and healthy volunteers (HVs) were enrolled and received a 10 g, 20 g, or 40 g dose lactose hydrogen breath test (LHBT) in a randomized, double-blinded, controlled trial. The lactase gene promoter region was sequenced. Breath samples and symptoms were acquired at baseline and every 15 min for 3 h (13 measurements). The detection rates of lactose malabsorption (LM) and lactose intolerance (LI) for a 4SLHBT that acquired four measurements at 0, 90, 120, and 180 min from the same data set were compared with the results of standard LHBT. RESULTS: Sixty IBS-D patients and 60 HVs were studied. The genotype in all participants was C/C-13910. LM and LI detection rates increased with lactose dose from 10 g, 20 g to 40 g in both groups (P < 0.001). 4SLHBT showed excellent diagnostic concordance with standard LHBT (97%-100%, Kappa​​ 0.815-0.942) with high sensitivity (90%-100%) and specificity (100%) at all three lactose doses in both groups. CONCLUSION: Reducing the number of measurements from 13 to 4 samples did not significantly impact on the accuracy of LHBT in health and IBS-D. 4SLHBT is a valid test for assessment of LM and LI in clinical practice. PMID:26140004

  10. Drunken driving and breath alcohol test at the scene of violence in Japan.

    PubMed

    Marumo, Y; Kishi, T; Seta, S

    1992-04-01

    Road Traffic Law prescribes that no person shall drive any vehicle under the influence of intoxicating liquor. Actually, determination of "influence of alcohol" is based on the standard set by the Cabinet Order that alcohol level exceeds 0.5 mg/ml of blood or 0.25 mg/l of expiration. In 1988, number of traffic accidents by drunken driving is 4,808 cases. Among the accidents by drunken driving the rate of fatal causes is 12%. During about last ten years, both of accidents and fatal cases by drunken driving have been decreasing in number, on the other hand, charged or cited number of violation involved "driving under the influence of alcohol" has been increasing. This fact indicates that the concept of seriousness of driving after heavy drinking has been diffused over Japanese nation, but there is still a tendency among drivers to consider the effect of alcohol on driving operation to be negligible when light drinking. In a sobriety checkpoint, alcohol field test are carried out on breath to screen out impaired driver. The most common device used in Japan is an alcohol detector tube, in which cerite particles coated with chromate are packed. The scale on the detector tube is marked to show a value that is lower by 20% than the actual value concerning its inaccuracy. In our study on accuracy of the alcohol detector tube using samples containing approximately 0.25 mg/l of alcohol, which is legal critical level of alcohol impairment, coefficients of variation were 1.50 to 5.45% and deviations from the analytical results by gas chromatography were 18.2 to 19.5%.

  11. Variables that Impact on the Results of Breath-Alcohol Tests

    ERIC Educational Resources Information Center

    Labianca, Dominick A.

    2004-01-01

    In a 2003 issue of the "Journal of Chemical Education," Kniesel and Bellamy describe a timely and pedagogically effective experiment involving breath-alcohol analysis using an FTIR (Fourier Transform Infrared Spectroscopy) spectrometer. The present article clarifies some of the information presented in the 2003 article.

  12. Breathing Problems

    MedlinePlus

    ... re not getting enough air. Sometimes mild breathing problems are from a stuffy nose or hard exercise. ... emphysema or pneumonia cause breathing difficulties. So can problems with your trachea or bronchi, which are part ...

  13. Breath holding spell

    MedlinePlus

    ... such as Riley-Day syndrome or Rett syndrome Iron deficiency anemia A family history of breath holding spells ( ... tests may be done to check for an iron deficiency. Other tests that may be done include: EKG ...

  14. [Test using vapourated expired nasal breathing in medicine 100 years ago and in paestum 2 300 years ago].

    PubMed

    Pirsig, W

    2014-11-01

    This historical sketch follows the traces of a mirror, once used to test the last breath of a dying woman. It was found on the fresco of a tomb in Paestum dated about 320 BC. In 1889, Hendrik Zwaardemaker (Utrecht) was the first to present a hygrometric functional test using a cold mirror placed under the nose to estimate the degree of airflow obstruction during exhalation. In 1901, Ernst Glatzel (Berlin) modified Zwaardemaker's concept by engraving a series of equidistant arcs into his metallic mirror to further quantify the amounts of condensed vapour in the expired air. The Glatzel-mirror was used in Germany until after the Second World War. PMID:25369157

  15. Influence of different proton pump inhibitors on activity of cytochrome P450 assessed by [(13)C]-aminopyrine breath test.

    PubMed

    Kodaira, Chise; Uchida, Shinya; Yamade, Mihoko; Nishino, Masafumi; Ikuma, Mutsuhiro; Namiki, Noriyuki; Sugimoto, Mitsushige; Watanabe, Hiroshi; Hishida, Akira; Furuta, Takahisa

    2012-03-01

    Aminopyrine is metabolized by cytochrome P450 (CYP) in the liver. The investigators evaluated influences of different PPIs on CYP activity as assessed by the [(13)C]-aminopyrine breath test ([(13)C]-ABT). Subjects were 15 healthy volunteers with different CYP2C19 status (5 rapid metabolizers [RMs], 5 intermediate metabolizers [IMs], and 5 poor metabolizers [PMs]). Breath samples were collected before and every 15 to 30 minutes for 3 hours after oral ingestion of [(13)C]-aminopyrine 100 mg on day 8 of each of the following regimens: control; omeprazole 20 mg and 80 mg, lansoprazole 30 mg, and rabeprazole 20 mg. Changes in carbon isotope ratios in carbon dioxide ((13)CO(2)/(12)CO(2)) in breath samples were measured by infrared spectrometry and expressed as delta-over-baseline (DOB) ratios (‰). Mean areas under the curve of DOB from 0 to 3 h (AUC(0-3h) of DOB) were significantly decreased by omeprazole 20 mg and lansoprazole 30 mg but not by rabeprazole 20 mg. Conversely, higher PPI dose (ie, omeprazole 80 mg) seemed to further decrease AUC(0-3h) of DOB in RMs but increased it in PMs. Omeprazole and lansoprazole at the standard doses inhibit CYP activity but rabeprazole does not, whereas high-dose omeprazole seems to induce CYPs. PMID:21415279

  16. Determination of kinetic parameters of fermentation processes by a continuous unsteady-state method: Application to the alcoholic fermentation of D-xylose by Pichia stipitis

    SciTech Connect

    Dominguez, H.; Nunez, M.J.; Lema, J.M. ); Chamy, R. )

    1993-05-01

    A quick technique for determination of kinetic parameters of fermentation processes is proposed and applied to the transformation of D-xylose into ethanol by Pichi stipitis. The commonly used method to evaluate these parameters is based on achieving several steady states. In the proposed procedure, [mu][sub m] and K[sub S] can be determined from only one steady state, by provoking a disturbance over it, after allowing the system to return to the original conditions. The main difference between the steady and unsteady state methods is the required fermentation time; while the former method lasted 350 h, the latter required a period 25 times lower. Kinetic and stoichiometric parameters were determined with both methods under anoxic and limited oxygen concentration conditions. Results from the two methods were compared, giving only 2% and 4.5% differences in the values of K[sub S] and [mu][sub m], respectively, under anoxic conditions; 12.5% for K[sub S] and a little over 4% for [mu][sub m] were the deviations under the latter ones.

  17. Ab Initio Molecular Dynamics Simulations of ..beta..-D-Glucose and ..beta..-D-Xylose Degradation Mechanisms in Acidic Aqueous Solution

    SciTech Connect

    Qian, X.; Nimlos, M. R.; Davis, M.; Johnson, D. K.; Himmel, M. E.

    2005-01-01

    Ab initio molecular dynamics simulations were employed to investigate, with explicit solvent water molecules, {beta}-d-glucose and {beta}-d-xylose degradation mechanisms in acidic media. The rate-limiting step in sugar degradation was found to be protonation of the hydroxyl groups on the sugar ring. We found that the structure of water molecules plays a significant role in the acidic sugar degradation pathways. Firstly, a water molecule competes with the hydroxyl group on the sugar ring for protons. Secondly, water forms hydrogen bonds with the hydroxyl groups on the sugar rings, thus weakening the C-C and C-O bonds (each to a different degree). Note that the reaction pathways could be altered due to the change of relative stability of the C-C and C-O bonds. Thirdly, water molecules that are hydrogen-bonded to sugar hydroxyls could easily extract a proton from the reaction intermediate, terminating the reaction. Indeed, the sugar degradation pathway is complex due to multiple protonation probabilities and the surrounding water structure. Our experimental data support multiple sugar acidic degradation pathways.

  18. Conversion of xylan, d-xylose and lignocellulosic biomass into furfural using AlCl3 as catalyst in ionic liquid.

    PubMed

    Zhang, Luxin; Yu, Hongbing; Wang, Pan; Dong, Heng; Peng, Xinhong

    2013-02-01

    In order to define a new green catalytic pathway for the production of furfural, the catalyzed conversion of xylan into furfural in 1-butyl-3-methylimidazolium chloride was studied by using mineral acids and metal chlorides as catalysts under microwave irradiation. Amongst these catalysts, AlCl(3) resulted in the highest furfural yield of 84.8% at 170°C for 10s. The effect of AlCl(3) on the conversion efficiency of d-xylose and untreated lignocellulosic biomass was also investigated, the yields of furfural from corncob, grass and pine wood catalyzed by AlCl(3) in [BMIM]Cl were in the range of 16-33%. [BMIM]Cl and AlCl(3) could be recycled for four runs with stable catalytic activity. AlCl(3) is less corrosive than mineral acids, and the use of ionic liquid as reaction medium will no longer generate toxic wastewater, thus this reaction system is more ecologically viable. PMID:23306118

  19. Bioconversion of D-glucose to D-psicose with immobilized D-xylose isomerase and D-psicose 3-epimerase on Saccharomyces cerevisiae spores.

    PubMed

    Li, Zijie; Li, Yi; Duan, Shenglin; Liu, Jia; Yuan, Peng; Nakanishi, Hideki; Gao, Xiao-Dong

    2015-08-01

    Saccharomyces cerevisiae spores are dormant cells, which can tolerate various types of environmental stress. In our previous work, we successfully developed biological and chemical methods for enzyme immobilization based on the structures of S. cerevisiae spore wall. In this study, we employed biological and chemical approaches for the immobilization of D-xylose isomerase (XI) from Thermus thermophilus and D-psicose 3-epimerase (DPEase) from Agrobacterium tumefaciens with yeast spores, respectively. The enzymatic properties of both immobilized XI and DPEase were characterized and the immobilized enzymes exhibit higher thermostability, broader pH tolerance, and good repeatability compared with free enzymes. Furthermore, we established a two-step approach for the bioconversion of D-glucose to D-psicose using immobilized enzymes. To improve the conversion yield, a multi-pot strategy was adopted for D-psicose production by repeating the two-step process continually. As a result, the yield of D-psicose was obviously improved and the highest yield reached about 12.0 %.

  20. Overexpression of the Aspergillus niger GatA transporter leads to preferential use of D-galacturonic acid over D-xylose

    PubMed Central

    2014-01-01

    Pectin is a structural heteropolysaccharide of the primary cell walls of plants and as such is a significant fraction of agricultural waste residues that is currently insufficiently used. Its main component, D-galacturonic acid, is an attractive substrate for bioconversion. The complete metabolic pathway is present in the genome of Aspergillus niger, that is used in this study. The objective was to identify the D-galacturonic acid transporter in A. niger and to use this transporter to study D-galacturonic acid metabolism. We have functionally characterized the gene An14g04280 that encodes the D-galacturonic acid transporter in A. niger. In a mixed sugar fermentation it was found that the An14g04280 overexpression strain, in contrast to the parent control strain, has a preference for D-galacturonic acid over D-xylose as substrate. Overexpression of this transporter in A. niger resulted in a strong increase of D-galacturonic acid uptake and induction of the D-galacturonic acid reductase activity, suggesting a metabolite controlled regulation of the endogenous D-galacturonic acid catabolic pathway. PMID:25177540

  1. 13C-Breath Tests for Sucrose Digestion in Congenital Sucrase Isomaltase Deficient and Sacrosidase Supplemented Patients

    PubMed Central

    Robayo-Torres, Claudia C.; Opekun, Antone R.; Quezada-Calvillo, Roberto; Xavier, Villa; Smith, E. O’Brian; Navarrete, Marilyn; Baker, S. Susan; Nichols, Buford L

    2008-01-01

    Congenital sucrase-isomaltase deficiency (CSID) is characterized by absence or deficiency of the mucosal sucrase-isomaltase enzyme. Specific diagnosis requires upper gastrointestinal biopsy with evidence of low to absent sucrase enzyme activity and normal histology. The hydrogen breath test (BT) is useful but is not specific for confirmation of CSID. We investigated a more specific 13C-sucrose labeled BT. Objectives were to determine if CSID can be detected with the 13C-sucrose BT without duodenal biopsy sucrase assay and if the 13C-sucrose BT can document restoration of sucrose digestion by CSID patients after oral supplementation with sacrosidase (Sucraid®). Methods Ten CSID patients were diagnosed by low biopsy sucrase activity. Ten controls were children who underwent endoscopy and biopsy because of dyspepsia or chronic diarrhea with normal mucosal enzymes activity and histology. Uniformly-labeled 13C-glucose and 13C-sucrose loads were orally administered. 13CO2 breath enrichments were assayed using an infrared spectrophotometer. In CSID patients the 13C-sucrose load was repeated adding Sucraid®. Sucrose digestion and oxidation were calculated as a mean % coefficient of glucose oxidation (% CGO) averaged between 30 and 90 minutes. Results Classification of patients by 13C-sucrose BT % CGO agreed with biopsy sucrase activity. The breath test also documented the return to normal of sucrose digestion and oxidation after supplementation of CSID patients with Sucraid®. Conclusion 13C-sucrose BT is an accurate and specific non-invasive confirmatory test for CSID and for enzyme replacement management. PMID:19330928

  2. How Accurate Are Blood (or Breath) Tests for Identifying Self-Reported Heavy Drinking Among People with Alcohol Dependence?

    PubMed Central

    Bertholet, Nicolas; Winter, Michael R.; Cheng, Debbie M.; Samet, Jeffrey H.; Saitz, Richard

    2014-01-01

    Aims Managing patients with alcohol dependence includes assessment for heavy drinking, typically by asking patients. Some recommend biomarkers to detect heavy drinking but evidence of accuracy is limited. Methods Among people with dependence, we assessed the performance of disialo-carbohydrate-deficient transferrin (%dCDT, ≥1.7%), gamma-glutamyltransferase (GGT, ≥66 U/l), either %dCDT or GGT positive, and breath alcohol (> 0) for identifying 3 self-reported heavy drinking levels: any heavy drinking (≥4 drinks/day or >7 drinks/week for women, ≥5 drinks/day or >14 drinks/week for men), recurrent (≥5 drinks/day on ≥5 days) and persistent heavy drinking (≥5 drinks/day on ≥7 consecutive days). Subjects (n = 402) with dependence and current heavy drinking were referred to primary care and assessed 6 months later with biomarkers and validated self-reported calendar method assessment of past 30-day alcohol use. Results The self-reported prevalence of any, recurrent and persistent heavy drinking was 54, 34 and 17%. Sensitivity of %dCDT for detecting any, recurrent and persistent self-reported heavy drinking was 41, 53 and 66%. Specificity was 96, 90 and 84%, respectively. %dCDT had higher sensitivity than GGT and breath test for each alcohol use level but was not adequately sensitive to detect heavy drinking (missing 34–59% of the cases). Either %dCDT or GGT positive improved sensitivity but not to satisfactory levels, and specificity decreased. Neither a breath test nor GGT was sufficiently sensitive (both tests missed 70–80% of cases). Conclusions Although biomarkers may provide some useful information, their sensitivity is low the incremental value over self-report in clinical settings is questionable. PMID:24740846

  3. Diving and foraging patterns of Marbled Murrelets (Brachyramphus marmoratus): Testing predictions from optimal-breathing models

    USGS Publications Warehouse

    Jodice, Patrick G.; Collopy, M.W.

    1999-01-01

    The diving behavior of Marbled Murrelets (Brachyramphus marmoratus) was studied using telemetry along the Oregon coast during the 1995 and 1996 breeding seasons and examined in relation to predictions from optimal-breathing models. Duration of dives, pauses, dive bouts, time spent under water during dive bouts, and nondiving intervals between successive dive bouts were recorded. Most diving metrics differed between years but not with oceanographic conditions or shore type. There was no effect of water depth on mean dive time or percent time spent under water even though dive bouts occurred in depths from 3 to 36 m. There was a significant, positive relationship between mean dive time and mean pause time at the dive-bout scale each year. At the dive-cycle scale, there was a significant positive relationship between dive time and preceding pause time in each year and a significant positive relationship between dive time and ensuing pause time in 1996. Although it appears that aerobic diving was the norm, there appeared to be an increase in anaerobic diving in 1996. The diving performance of Marbled Murrelets in this study appeared to be affected by annual changes in environmental conditions and prey resources but did not consistently fit predictions from optimal-breathing models.

  4. Genomic analysis and D-xylose fermentation of three novel Spathaspora species: Spathaspora girioi sp. nov., Spathaspora hagerdaliae f. a., sp. nov. and Spathaspora gorwiae f. a., sp. nov.

    PubMed

    Lopes, Mariana R; Morais, Camila G; Kominek, Jacek; Cadete, Raquel M; Soares, Marco A; Uetanabaro, Ana Paula T; Fonseca, César; Lachance, Marc-André; Hittinger, Chris Todd; Rosa, Carlos A

    2016-06-01

    Three novel D-xylose-fermenting yeast species of Spathaspora clade were recovered from rotting wood in regions of the Atlantic Rainforest ecosystem in Brazil. Differentiation of new species was based on analyses of the gene encoding the D1/D2 sequences of large subunit of rRNA and on 642 conserved, single-copy, orthologous genes from genome sequence assemblies from the newly described species and 15 closely-related Debaryomycetaceae/Metschnikowiaceae species. Spathaspora girioi sp. nov. produced unconjugated asci with a single elongated ascospore with curved ends; ascospore formation was not observed for the other two species. The three novel species ferment D-xylose with different efficiencies. Spathaspora hagerdaliae sp. nov. and Sp. girioi sp. nov. showed xylose reductase (XR) activity strictly dependent on NADPH, whereas Sp. gorwiae sp. nov. had XR activity that used both NADH and NADPH as co-factors. The genes that encode enzymes involved in D-xylose metabolism (XR, xylitol dehydrogenase and xylulokinase) were also identified for these novel species. The type strains are Sp. girioi sp. nov. UFMG-CM-Y302(T) (=CBS 13476), Sp. hagerdaliae f.a., sp. nov. UFMG-CM-Y303(T) (=CBS 13475) and Sp. gorwiae f.a., sp. nov. UFMG-CM-Y312(T) (=CBS 13472). PMID:27188884

  5. Genomic analysis and D-xylose fermentation of three novel Spathaspora species: Spathaspora girioi sp. nov., Spathaspora hagerdaliae f. a., sp. nov. and Spathaspora gorwiae f. a., sp. nov.

    PubMed

    Lopes, Mariana R; Morais, Camila G; Kominek, Jacek; Cadete, Raquel M; Soares, Marco A; Uetanabaro, Ana Paula T; Fonseca, César; Lachance, Marc-André; Hittinger, Chris Todd; Rosa, Carlos A

    2016-06-01

    Three novel D-xylose-fermenting yeast species of Spathaspora clade were recovered from rotting wood in regions of the Atlantic Rainforest ecosystem in Brazil. Differentiation of new species was based on analyses of the gene encoding the D1/D2 sequences of large subunit of rRNA and on 642 conserved, single-copy, orthologous genes from genome sequence assemblies from the newly described species and 15 closely-related Debaryomycetaceae/Metschnikowiaceae species. Spathaspora girioi sp. nov. produced unconjugated asci with a single elongated ascospore with curved ends; ascospore formation was not observed for the other two species. The three novel species ferment D-xylose with different efficiencies. Spathaspora hagerdaliae sp. nov. and Sp. girioi sp. nov. showed xylose reductase (XR) activity strictly dependent on NADPH, whereas Sp. gorwiae sp. nov. had XR activity that used both NADH and NADPH as co-factors. The genes that encode enzymes involved in D-xylose metabolism (XR, xylitol dehydrogenase and xylulokinase) were also identified for these novel species. The type strains are Sp. girioi sp. nov. UFMG-CM-Y302(T) (=CBS 13476), Sp. hagerdaliae f.a., sp. nov. UFMG-CM-Y303(T) (=CBS 13475) and Sp. gorwiae f.a., sp. nov. UFMG-CM-Y312(T) (=CBS 13472).

  6. Lactose malabsorption testing in daily clinical practice: a critical retrospective analysis and comparison of the hydrogen/methane breath test and genetic test (c/t-13910 polymorphism) results.

    PubMed

    Enko, Dietmar; Rezanka, Erwin; Stolba, Robert; Halwachs-Baumann, Gabriele

    2014-01-01

    The aim of this study was to establish a retrospective evaluation and comparison of the hydrogen/methane (H2/CH4) breath test and genetic test (C/T-13910 polymorphism) results in lactose malabsorption testing. In total 263 consecutive patients with suspected lactose malabsorption were included in this study. They underwent the H2/CH4 breath test following the ingestion of 50 g lactose and were tested for the C/T-13910 polymorphism. In total 51 patients (19.4%) had a C/C-13910 genotype, indicating primary lactose malabsorption. Only 19 patients (7.2%) also had a positive H2/CH4 breath test. All in all 136 patients (51.69%) had a C/T-13910 and 76 patients (28.91%) a T/T-13910 genotype, indicating lactase persistence. Four patients (1.5%) with the C/T-13910 genotype and one patient (0.4%) with the T/T-13910 genotype had a positive H2/CH4 breath test result, indicating secondary lactose malabsorption. Cohen's Kappa measuring agreement between the two methods was 0.44. Twenty patients (7.6%) with a positive H2/CH4 peak within 60 minutes after lactose ingestion were classified as patients with lactose-dependent small intestinal bacterial overgrowth (SIBO). In conclusion, only moderate agreement between the breath test and the genetic test was shown. Secondary lactose malabsorption as well as preanalytical limitations of the combined H2/CH4 breath test procedure can cause discrepant results. This trial is registered with K-42-13. PMID:24829570

  7. Lactose Malabsorption Testing in Daily Clinical Practice: A Critical Retrospective Analysis and Comparison of the Hydrogen/Methane Breath Test and Genetic Test (C/T−13910 Polymorphism) Results

    PubMed Central

    Rezanka, Erwin; Stolba, Robert; Halwachs-Baumann, Gabriele

    2014-01-01

    The aim of this study was to establish a retrospective evaluation and comparison of the hydrogen/methane (H2/CH4) breath test and genetic test (C/T−13910 polymorphism) results in lactose malabsorption testing. In total 263 consecutive patients with suspected lactose malabsorption were included in this study. They underwent the H2/CH4 breath test following the ingestion of 50 g lactose and were tested for the C/T−13910 polymorphism. In total 51 patients (19.4%) had a C/C−13910 genotype, indicating primary lactose malabsorption. Only 19 patients (7.2%) also had a positive H2/CH4 breath test. All in all 136 patients (51.69%) had a C/T−13910 and 76 patients (28.91%) a T/T−13910 genotype, indicating lactase persistence. Four patients (1.5%) with the C/T−13910 genotype and one patient (0.4%) with the T/T−13910 genotype had a positive H2/CH4 breath test result, indicating secondary lactose malabsorption. Cohen's Kappa measuring agreement between the two methods was 0.44. Twenty patients (7.6%) with a positive H2/CH4 peak within 60 minutes after lactose ingestion were classified as patients with lactose-dependent small intestinal bacterial overgrowth (SIBO). In conclusion, only moderate agreement between the breath test and the genetic test was shown. Secondary lactose malabsorption as well as preanalytical limitations of the combined H2/CH4 breath test procedure can cause discrepant results. This trial is registered with K-42-13. PMID:24829570

  8. Fabry-Perot microcavity sensor for H2-breath-test analysis

    NASA Astrophysics Data System (ADS)

    Vincenti, Maria Antonietta; De Sario, Marco; Petruzzelli, V.; D'Orazio, Antonella; Prudenzano, Francesco; de Ceglia, Domenico; Scalora, Michael

    2007-10-01

    Leak detection of hydrogen for medical purposes, based on the monitoring of the optical response of a simple Fabry-Perot microcavity, is proposed to investigate either the occurrence of lactose intolerance, or lactose malabsorption condition. Both pathologic conditions result in bacterial overgrowth in the intestine, which causes increased spontaneous emission of H2 in the human breath. Two sensitivity figures of merit are introduced to inspect changes in the sensor response, and to relate the microcavity response to a pathologic condition, which is strictly related to a different level of exhaled hydrogen. Different sensor configurations using a metal-dielectric microcavity are reported and discussed in order to make the most of the well-known ability of palladium to spontaneously absorb hydrogen.

  9. The 13C-mixed triglyceride breath test in healthy adults: determinants of the 13CO2 response.

    PubMed

    Kalivianakis, M; Verkade, H J; Stellaard, F; van der Were, M; Elzinga, H; Vonk, R J

    1997-05-01

    Defects in lipolysis due to pancreatic insufficiency can be diagnosed by the mixed triglyceride (MTG) 13CO2 breath test. However, the effects of various test conditions on the 13CO2 response have only been partially elucidated. In healthy adults, we performed the 13CO2 mixed triglyceride breath test and we compared (a) the inter- and intra-individual variation in the 13CO2 response; (b) the effect of two different test meals; (c) the effect of an additional meal during the test; and (d) the effect of physical exercise during the test. Upon repeating the test in the same individual (test meal cream), repeatability coefficients were large, with respect to either time to maximum 13C excretion rate (3.8 h). maximum 13C excretion rate (4.9% 13C dose h-1) or cumulative recovery of 13C over the 9-h study period (22.7% 13C dose). The cumulative 13C expiration over 9 h obtained with the test meal composed of cream was quantitatively similar to that obtained with bread and butter: 42.2 +/- 8.4% and 47.7 +/- 6.3% respectively. Fasting for 9 h during the test resulted in similar 13C expiration rates and cumulative 13C expiration (43.4% +/- 7.2%) when compared with consumption of an additional meal 3 h after the start of the test (38.3 +/- 5.3%). The 13CO2 response increased in five out of seven subjects, but decreased in the other two, when moderate exercise was performed (bicycle ergometer, 50 W for 5 h). We conclude that the repeatability of the MTG test in healthy adults is low. The present results indicate that a solid and a liquid test meal, containing a similar amount of fats, give similar cumulative 13CO2 responses, and that stringent prolonged fasting during the test is unnecessary. Standardization of physical activity seems preferable, since the unequivocal effects of moderate exercise on the 13CO2 response were observed in the individuals studied. PMID:9179552

  10. Excellent agreement between genetic and hydrogen breath tests for lactase deficiency and the role of extended symptom assessment.

    PubMed

    Pohl, D; Savarino, E; Hersberger, M; Behlis, Z; Stutz, B; Goetze, O; Eckardstein, A V; Fried, M; Tutuian, R

    2010-09-01

    Clinical manifestations of lactase (LCT) deficiency include intestinal and extra-intestinal symptoms. Lactose hydrogen breath test (H2-BT) is considered the gold standard to evaluate LCT deficiency (LD). Recently, the single-nucleotide polymorphism C/T(-13910) has been associated with LD. The objectives of the present study were to evaluate the agreement between genetic testing of LCT C/T(-13910) and lactose H2-BT, and the diagnostic value of extended symptom assessment. Of the 201 patients included in the study, 194 (139 females; mean age 38, range 17-79 years, and 55 males, mean age 38, range 18-68 years) patients with clinical suspicion of LD underwent a 3-4 h H2-BT and genetic testing for LCT C/T(-13910). Patients rated five intestinal and four extra-intestinal symptoms during the H2-BT and then at home for the following 48 h. Declaring H2-BT as the gold standard, the CC(-13910) genotype had a sensitivity of 97% and a specificity of 95% with a κ of 0.9 in diagnosing LCT deficiency. Patients with LD had more intense intestinal symptoms 4 h following the lactose challenge included in the H2-BT. We found no difference in the intensity of extra-intestinal symptoms between patients with and without LD. Symptom assessment yielded differences for intestinal symptoms abdominal pain, bloating, borborygmi and diarrhoea between 120 min and 4 h after oral lactose challenge. Extra-intestinal symptoms (dizziness, headache and myalgia) and extension of symptom assessment up to 48 h did not consistently show different results. In conclusion, genetic testing has an excellent agreement with the standard lactose H2-BT, and it may replace breath testing for the diagnosis of LD. Extended symptom scores and assessment of extra-intestinal symptoms have limited diagnostic value in the evaluation of LD.

  11. Quantification of Helicobacter pylori infection in gastritis and ulcer disease using a simple and rapid carbon-14-urea breath test

    SciTech Connect

    Debongnie, J.C.; Pauwels, S.; Raat, A.; de Meeus, Y.; Haot, J.; Mainguet, P. )

    1991-06-01

    Gastric urease was studied isotopically in 230 patients with biopsy-proven normal mucosa or chronic gastritis, including 59 patients with ulcer disease. Carbon-14-urea was given in 25 ml of water without substrate carrier or nutrient-dense meal, and breath samples were collected over a 60-min period. The amount of 14CO2 excreted at 10 min was independent of the rate of gastric emptying and was not quantitatively influenced by the buccal urease activity. The 10-min 14CO2 values discriminated well between Helicobacter pylori positive and negative patients (94% sensitivity, 89% specificity) and correlated with the number of organisms assessed by histology. The test was a good predictor of chronic gastritis (95% sensitivity and 96% specificity), and a quantitative relationship was observed between 14CO2 values and the severity and activity of the gastritis. In H. pylori positive patients, breath 14CO2 was found to be similar in patients with and without ulcer disease, suggesting that the number of bacteria is not a determining factor for the onset of ulceration.

  12. Measurements of substrate oxidation using (13)CO 2-breath testing reveals shifts in fuel mix during starvation.

    PubMed

    McCue, Marshall D; Pollock, Erik D

    2013-12-01

    Most fasting animals are believed to sequentially switch from predominantly utilizing one metabolic substrate to another from carbohydrates, to lipids, then to proteins. The timing of these physiological transitions has been estimated using measures of substrate oxidation including changes in respiratory exchange ratios, blood metabolites, nitrogen excretion, or enzyme activities in tissues. Here, we demonstrate how (13)CO2-breath testing can be used to partition among the oxidation of distinct nutrient pools in the body (i.e., carbohydrates, lipids, and proteins) that have become artificially enriched in (13)C. Seventy-two Swiss Webster mice were raised to adulthood on diets supplemented with (13)C-1-L-leucine, (13)C-1-palmitic acid, (13)C-1-D-glucose, or no tracer. Mice were then fasted for 72 h during which [Formula: see text], [Formula: see text], δ(13)C of exhaled CO2, body temperature, body mass, and blood metabolites (i.e., glucose, ketone bodies, and triacylglycerols) were measured. The fasting mice exhibited reductions in body mass (29 %), body temperature (3.3 °C), minimum observed metabolic rates (24 %), and respiratory exchange ratio (0.18), as well as significant changes in blood metabolites; but these responses were not particularly indicative of changes in oxidative fuel mixture. Measurements of endogenous nutrient oxidation by way of (13)CO2-breath testing revealed a decrease in the rate of oxidation of carbohydrates from 61 to 10 % of the total energy expenditure during the first 6 h without food. This response was mirrored by a coincidental increase in rate of endogenous lipid oxidation from 18 to 64 %. A transient peak in carbohydrate oxidation occurred between 8 and 14 h, presumably during increased glycogen mobilization. A well-defined period of protein sparing between 8 and 12 h was observed where endogenous protein oxidation accounted for as little as 8 % of the total energy expenditure. Thereafter, protein oxidation continually

  13. Sensitivity of bile acid breath test in the diagnosis of bacterial overgrowth in the small intestine with and without the stagnant (blind) loop syndrome.

    PubMed

    Farivar, S; Fromm, H; Schindler, D; Schmidt, F W

    1979-01-01

    The bile acid breath test was studied to examine its sensitivity for establishing the diagnosis of bacterial overgrowth in comparison to that of the Schilling test and small-intestinal cultures in 12 patients with a stagnant (blind) loop syndrome, as well as in 38 patients who had other conditions with suspected bacterial contamination of the small intestine. The presence of bile acid malabsorption was excluded in all 50 patients by studies of fecal excretion of radioactively labeled bile acids. The bile acid breath test was positive in 100% (12/12) of the patients with a stagnant (blind) loop syndrome, whereas 92% (11/12) had a positive Schilling test and 75% (9/12) a positive small-intestinal culture. The abnormal tests improved only in 2 of 4 patients treated with tetracycline. In the group of 38 patients without demonstrable dilated or blind loops of small bowel who were suspected of having bacterial contamination of small bowel, the bile acid breath test was positive in 53% (20/38), the Schilling test in 39% (15/38), and the small-intestinal culture in 45% (17/38). The difference in the incidence of positive results between the tests in the two patient groups was statistically not significant. The findings of these studies have the following diagnostic implications: (1) Bile acid breath test, Schilling test, and cultures of aspirates from the upper small bowel are of comparable sensitivity in the detection of bacterial overgrowth in the small intestine. (2) A negative bile acid breath test makes the diagnosis of a stagnant (blind) loop syndrome very unlikely.

  14. Bad Breath

    MedlinePlus

    ... hygiene leads to bad breath because when food particles are left in your mouth, they can rot ... Flossing once a day helps get rid of particles wedged between your teeth. Also, visit your dentist ...

  15. Detection of inner tube defects in co-axial circle and Bain breathing systems: a comparison of occlusion and Pethick tests.

    PubMed

    Szypula, K A; Ip, J K; Bogod, D; Yentis, S M

    2008-10-01

    The performance of the occlusion and Pethick tests in detecting faulty inner tubes in co-axial circle and Bain systems was compared. Twelve co-axial circle and 12 Bain anaesthetic breathing systems were tested using the occlusion and the Pethick tests. For each system, three tubes were intact, and the remaining nine had a defect deliberately created in the inner tube (three proximal, three middle and three distal). The investigators were blinded to which of the tubes were defective, and to each other's results. The results showed 100% specificity for both tests. The sensitivity of the occlusion test for detecting faulty breathing systems was found to be good (98%). Our results suggest that the occlusion test should be performed in preference to the Pethick test when testing co-axial circle and Bain systems.

  16. Breathing metabolic simulator

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G., Jr.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    A description is given of an automatic computer controlled second generation breathing metabolic simulator (BMS). The simulator is used for evaluating and testing respiratory diagnostic, monitoring, support, and resuscitation equipment. Any desired sequence of metabolic activities can be simulated on the device for up to 15 hours. The computer monitors test procedures and provides printouts of test results.

  17. Cardiogenic oscillation phase relationships during single-breath tests performed in microgravity

    NASA Technical Reports Server (NTRS)

    Lauzon, A. M.; Elliott, A. R.; Paiva, M.; West, J. B.; Prisk, G. K.

    1998-01-01

    We studied the phase relationships of the cardiogenic oscillations in the phase III portion of single-breath washouts (SBW) in normal gravity (1 G) and in sustained microgravity (microG). The SBW consisted of a vital capacity inspiration of 5% He-1.25% sulfurhexafluoride-balance O2, preceded at residual volume by a 150-ml Ar bolus. Pairs of gas signals, all of which still showed cardiogenic oscillations, were cross-correlated, and their phase difference was expressed as an angle. Phase relationships between inspired gases (e.g., He) and resident gas (n2) showed no change from 1 G (211 +/- 9 degrees) to microG (163 +/- 7 degrees). Ar bolus and He were unaltered between 1 G (173 +/- 15 degrees) and microG (211 +/- 25 degrees), showing that airway closure in microG remains in regions of high specific ventilation and suggesting that airway closure results from lung regions reaching low regional volume near residual volume. In contrast, CO2 reversed phase with He between 1 G (332 +/- 6 degrees) and microG (263 +/- 27 degrees), strongly suggesting that, in microG, areas of high ventilation are associated with high ventilation-perfusion ratio (VA/Q). This widening of the range of VA/Q in microG may explain previous measurements (G.K. Prisk, A.R. Elliott, H.J.B. Guy, J.M. Kosonen, and J.B. West J. Appl. Physiol. 79: 1290-1298, 1995) of an overall unaltered range of VA/Q in microG, despite more homogeneous distributions of both ventilation and perfusion.

  18. Cardiovascular Biomarkers In Exhaled Breath

    PubMed Central

    Cikach, Frank S.; Dweik, Raed A.

    2014-01-01

    With each breath we exhale, thousands of molecules are expelled in our breath giving individuals a “breath-print” that can tell a lot about them and their state of health. Breath analysis is rapidly evolving as the new frontier in medical testing. The end of the 20th century and the beginning of the 21st century have arguably witnessed a revolution in our understanding of the constituents of exhaled breath and the development of the field of breath analysis and testing. Thanks to major breakthroughs in new technologies (infrared, electrochemical, chemiluminescence, and others) and the availability of mass spectrometers, the field of breath analysis has made considerable advances in the 21st century. Several methods are now in clinical use or nearly ready to enter that arena. Breath analysis has the potential to offer relatively inexpensive, rapid, noninvasive methods for detecting and/or monitoring a variety of diseases. Breath analysis also has applications in fields beyond medicine, including environmental monitoring, security and others. This review will focus on exhaled breath as a potential source of biomarkers for medical applications with specific attention to applications (and potential applications) in cardiovascular disease. PMID:22824108

  19. Estimation of Insulin Resistance in Mexican Adults by the [(13)C]Glucose Breath Test Corrected for Endogenous Total CO(2) Production.

    PubMed

    Ibarra-Pastrana, Erika; Candia Plata, Maria Del Carmen; Alvarez, Gerardo; Valencia, Mauro E

    2012-01-01

    Objective. To evaluate the efficacy of the [(13)C]glucose breath test for measuring insulin resistance in Mexican adults with different glycemic states. Research Design and Methods. Fifty-eight adults underwent a [(13)C]glucose breath test with simultaneous measurement of total CO(2) production by indirect calorimetry, at baseline and 90 minutes after the ingestion of 15 g of dextrose and 25 mg of [(13)C]glucose. HOMA was used as a marker of insulin resistance. Results. We found an inverse correlation between HOMA and the breath test δ(13)CO(2) (‰), r = -0.41 (P = 0.001). After adjusting for total CO(2) production, correlations between HOMA and fasting glucose were less strong but remained significant. An ROC curve was constructed using δ(13)CO(2) (‰) and HOMA values; the cut-off point was 9.99‰ δ(13)CO(2), corresponding to a sensitivity of 80.0 (95% CI: 51.9, 95.7) and a specificity of 67.4 (95% CI: 51.5, 80.9). Conclusions. The [(13)C]glucose breath test is a simple noninvasive procedure but was not sufficiently robust for an accurate diagnosis of insulin resistance. Our findings suggest that the test might be helpful in identifying individuals who are not IR, which in turn may contribute to improved diabetes prevention.

  20. Occult H. pylori infection partially explains ‘false-positive’ results of 13C-urea breath test

    PubMed Central

    Ramírez-Lázaro, María J; Lario, Sergio; Sánchez-Delgado, Jordi; Montserrat, Antònia; Quílez, Elisa M; Casalots, Alex; Suarez, David; Campo, Rafel; Brullet, Enric; Junquera, Félix; Sanfeliu, Isabel; Segura, Ferran

    2015-01-01

    Background In a previous study, UBiT-100 mg, (Otsuka, Spain), a commercial 13C-urea breath test omitting citric acid pre-treatment, had a high rate of false-positive results; however, it is possible that UBiT detected low-density ‘occult’ infection missed by other routine reference tests. We aimed to validate previous results in a new cohort and to rule out the possibility that false-positive UBiT were due to an ‘occult’ infection missed by reference tests. Methods Dyspeptic patients (n = 272) were prospectively enrolled and UBiT was performed, according to the manufacturer’s recommendations. Helicobacter pylori infection was determined by combining culture, histology and rapid urease test results. We calculated UBiT sensitivity, specificity, positive and negative predictive values (with 95% CI). In addition, we evaluated ‘occult’ H. pylori infection using two previously-validated polymerase chain reaction (PCR) methods for urease A (UreA) and 16 S sequences in gastric biopsies. We included 44 patients with a false-positive UBiT, and two control groups of 25 patients each, that were positive and negative for all H. pylori tests. Results UBiT showed a false-positive rate of 17%, with a specificity of 83%. All the positive controls and 12 of 44 patients (27%) with false-positive UBiT were positive for all two PCR tests; by contrast, none of our negative controls had two positive PCR tests. Conclusions UBiT suffers from a high rate of false-positive results and sub-optimal specificity, and the protocol skipping citric acid pre-treatment should be revised; however, low-density ‘occult’ H. pylori infection that was undetectable by conventional tests accounted for around 25% of the ‘false-positive’ results. PMID:26535122

  1. Carbon sequestration and estimated carbon credit values as measured using 13C labelling and analysis by means of an optical breath test analyser.

    PubMed

    Hood, R C; Khan, M; Haque, A; Khadir, M; Bonetto, J P; Syamsul, R; Mayr, L; Heiling, M

    2004-05-01

    Recent developments in optical systems (isotope-selective non-dispersive infrared spectrometry) for breath testing have provided a robust, low-cost option for undertaking (13)C analysis. Although these systems were initially developed for breath testing for Helicobacter pylori, they have an enormous potential as a soil science research tool. The relatively low cost of the equipment, US$15,000-25,000, is within the research budgets of most institutes or universities. The simplicity of the mechanisms and optical nature mean that the equipment requires relatively low maintenance and minimal training. Thus methods were developed to prepare soil and plant materials for analysis using the breath test analyser. Results that compare conventional mass spectrometric methods with the breath test analyser will be presented. In combination with simple (13)C-plant-labeling techniques it is possible to devise methods for estimating carbon sequestration under different agronomic management practices within a short time frame. This enables assessment of the carbon credit value of a particular agronomic practice, which can in turn be used by policy makers for decision-making purposes. For global understanding of the effect of agricultural practices on the carbon cycle, data are required from a range of cropping systems and agro-ecological zones. The method and the approach described will enable collection of hard data within a reasonable time.

  2. Prevalence of alcohol-impaired drivers based on random breath tests in a roadside survey in Catalonia (Spain).

    PubMed

    Alcañiz, Manuela; Guillén, Montserrat; Santolino, Miguel; Sánchez-Moscona, Daniel; Llatje, Oscar; Ramon, Lluís

    2014-04-01

    Sobriety checkpoints are not usually randomly located by traffic authorities. As such, information provided by non-random alcohol tests cannot be used to infer the characteristics of the general driving population. In this paper a case study is presented in which the prevalence of alcohol-impaired driving is estimated for the general population of drivers. A stratified probabilistic sample was designed to represent vehicles circulating in non-urban areas of Catalonia (Spain), a region characterized by its complex transportation network and dense traffic around the metropolis of Barcelona. Random breath alcohol concentration tests were performed during spring 2012 on 7596 drivers. The estimated prevalence of alcohol-impaired drivers was 1.29%, which is roughly a third of the rate obtained in non-random tests. Higher rates were found on weekends (1.90% on Saturdays and 4.29% on Sundays) and especially at night. The rate is higher for men (1.45%) than for women (0.64%) and it shows an increasing pattern with age. In vehicles with two occupants, the proportion of alcohol-impaired drivers is estimated at 2.62%, but when the driver was alone the rate drops to 0.84%, which might reflect the socialization of drinking habits. The results are compared with outcomes in previous surveys, showing a decreasing trend in the prevalence of alcohol-impaired drivers over time.

  3. Evaporative emissions in three-day diurnal breathing loss tests on passenger cars for the Japanese market

    NASA Astrophysics Data System (ADS)

    Yamada, Hiroyuki; Inomata, Satoshi; Tanimoto, Hiroshi

    2015-04-01

    Breakthrough emissions that dominate diurnal evaporative emissions from gasoline vehicles were observed in continuous 3-day diurnal breathing loss (DBL) tests. These measurements were conducted on nine vehicles for the Japanese market. Two of these vehicles, made by US and European manufacturers, also meet regulations in their countries of origin. Four vehicles exhibited marked emissions caused by breakthrough emissions during the experimental period, all made by Japanese manufacturers. Using our experimental results, we estimate the total diurnal evaporative emissions from gasoline vehicles in Japan to be 32,792 t y-1. The compositions of the breakthrough and permeation emissions were analyzed in real time using proton transfer reaction plus switchable reagent ion mass spectrometry to estimate the ozone formation potential for the evaporative emissions. The real-time measurements showed that the adsorption of hydrocarbons in a sealed housing evaporative determination unit can result in underestimation, when concentrations are only monitored before and after a DBL test. The composition analysis gave an estimated maximum incremental reactivity (MIR) 20% higher for the breakthrough emissions than for the gasoline that was tested, while the MIR for the permeation emissions was almost the same as the MIR for the fuel. Evaporative emissions from gasoline vehicles in Japan were found to contribute 4.2% to emissions from stationary sources using a mass-based estimate, or 6.1% of emissions from stationary sources using a MIR-based estimate.

  4. Multiple-Breath Washout as a Lung Function Test in Cystic Fibrosis. A Cystic Fibrosis Foundation Workshop Report.

    PubMed

    Subbarao, Padmaja; Milla, Carlos; Aurora, Paul; Davies, Jane C; Davis, Stephanie D; Hall, Graham L; Heltshe, Sonya; Latzin, Philipp; Lindblad, Anders; Pittman, Jessica E; Robinson, Paul D; Rosenfeld, Margaret; Singer, Florian; Starner, Tim D; Ratjen, Felix; Morgan, Wayne

    2015-06-01

    The lung clearance index (LCI) is a lung function parameter derived from the multiple-breath washout (MBW) test. Although first developed 60 years ago, the technique was not widely used for many years. Recent technological advances in equipment design have produced gains in popularity for this test among cystic fibrosis (CF) researchers and clinicians, particularly for testing preschool-aged children. LCI has been shown to be feasible and sensitive to early CF lung disease in patients of all ages from infancy to adulthood. A workshop was convened in January 2014 by the North American Cystic Fibrosis Foundation to determine the readiness of the LCI for use in multicenter clinical trials as well as clinical care. The workshop concluded that the MBW text is a valuable potential outcome measure for CF clinical trials in preschool-aged patients and in older patients with FEV1 in the normal range. However, gaps in knowledge about the choice of device, gas, and standardization across systems are key issues precluding its use as a clinical trial end point in infants. Based on the current evidence, there are insufficient data to support the use of LCI or MBW parameters in the routine clinical management of patients with CF. PMID:26075554

  5. [COMPARATIVE EVALUATION OF THE EFFECTIVENESS OF THE USE OF 13C-LABELED MIXED TRIGLYCERIDE AND 13C-STARCH BREATH TESTS IN PATIENTS WITH CHRONIC PANCREATITIS AFTER CHOLECYSTECTOMY].

    PubMed

    Sirchak, Ye S

    2015-01-01

    The results of a comprehensive study of 96 patients after cholecystectomy are provided. The higher sensitivity and informativeness of the 13C-labeled mixed triglyceride breath .test compared with 13C-starch breath test for determining functional pancreatic insufficiency in patients after cholecystectomy in early stages of its formation was set. PMID:27491156

  6. How to breathe when you are short of breath

    MedlinePlus

    Pursed lip breathing; COPD - pursed lip breathing; Emphysema - pursed lip breathing; Chronic bronchitis - pursed lip breathing; Pulmonary fibrosis - pursed lip breathing; Interstitial lung disease - pursed lip breathing; Hypoxia - pursed lip breathing; ...

  7. An inventory of aeronautical ground research facilities. Volume 2: Air breathing engine test facilities

    NASA Technical Reports Server (NTRS)

    Pirrello, C. J.; Hardin, R. D.; Heckart, M. V.; Brown, K. R.

    1971-01-01

    The inventory covers free jet and direct connect altitude cells, sea level static thrust stands, sea level test cells with ram air, and propulsion wind tunnels. Free jet altitude cells and propulsion wind tunnels are used for evaluation of complete inlet-engine-exhaust nozzle propulsion systems under simulated flight conditions. These facilities are similar in principal of operation and differ primarily in test section concept. The propulsion wind tunnel provides a closed test section and restrains the flow around the test specimen while the free jet is allowed to expand freely. A chamber of large diameter about the free jet is provided in which desired operating pressure levels may be maintained. Sea level test cells with ram air provide controlled, conditioned air directly to the engine face for performance evaluation at low altitude flight conditions. Direct connect altitude cells provide a means of performance evaluation at simulated conditions of Mach number and altitude with air supplied to the flight altitude conditions. Sea level static thrust stands simply provide an instrumented engine mounting for measuring thrust at zero airspeed. While all of these facilities are used for integrated engine testing, a few provide engine component test capability.

  8. /sup 14/C-lactose breath tests during pelvic radiotherapy: the effect of the amount of small bowel irradiated

    SciTech Connect

    Weiss, R.G.; Stryker, J.A.

    1982-02-01

    Thirty patients who were undergoing pelvic radiotherapy had /sup 14/C-lactose breath tests performed in the first and fifth weeks of treatment. In Group I (21 patients), a significant portion of the small intestine was irradiated, and in Group II (9 patients), only a small portion of the small intestine was irradiated. In Group I, the average reductions in the excretion of ingested /sup 14/C between the first- and fifth-week tests were 41.5% at 1/2 hour postingestion (p less than 0.05), and 21.8% at 1 hour postingestion (p less than 0.05). In Group II, the percentage reductions were 11.8% and 3.7% at 1/2 and 1 hour, respectively (p greater than 0.05). The data suggest that lactose malabsorption is a factor in the etiology of the nausea, vomiting, and diarrhea experienced by patients who are undergoing pelvic radiotherapy, and that the amount of bowel included in the treatment volume significantly influences the degree of malabsorption.

  9. /sup 14/C-lactose breath tests during pelvic radiotherapy: the effect of the amount of small bowel irradiated

    SciTech Connect

    Weiss, R.G.; Stryker, J.A.

    1982-02-01

    Thirty patients who were undergoing pelvic radiotherapy had /sup 14/C-lactose breath tests performed in the first and fifth weeks of treatment. In Group I (21 patients), a significant portion of the small intestine was irradiated, and in Group II (9 patients), only a small portion of the small intestine was irradiated. In Group I, the average reductions in the excretion of ingested /sup 14/C between the first- and fifth-week tests were 41.5% at 1/2 hour postingestion (p<0.05), and 21.8% at 1 hour postingestion (p<0.05). In Group II, the prercentage reduction were 11.8% and 3.7% at 1/2 and 1 hour, respectively (p>0.05). The data suggest that lactose malabsorption is a factor in the etiology of the nausea, vomiting, and diarrhea experienced by patients who are undergoing pelvic radiotherapy, and that the amount of bowel included in the treatment volume significantly influences the degree of malabsorption.

  10. Design, fabrication and testing of an air-breathing micro direct methanol fuel cell with compound anode flow field

    NASA Astrophysics Data System (ADS)

    Wang, Luwen; Zhang, Yufeng; Zhao, Youran; An, Zijiang; Zhou, Zhiping; Liu, Xiaowei

    2011-10-01

    An air-breathing micro direct methanol fuel cell (μDMFC) with a compound anode flow field structure (composed of the parallel flow field and the perforated flow field) is designed, fabricated and tested. To better analyze the effect of the compound anode flow field on the mass transfer of methanol, the compound flow field with different open ratios (ratio of exposure area to total area) and thicknesses of current collectors is modeled and simulated. Micro process technologies are employed to fabricate the end plates and current collectors. The performances of the μDMFC with a compound anode flow field are measured under various operating parameters. Both the modeled and the experimental results show that, comparing the conventional parallel flow field, the compound one can enhance the mass transfer resistance of methanol from the flow field to the anode diffusion layer. The results also indicate that the μDMFC with an anode open ratio of 40% and a thickness of 300 µm has the optimal performance under the 7 M methanol which is three to four times higher than conventional flow fields. Finally, a 2 h stability test of the μDMFC is performed with a methanol concentration of 7 M and a flow velocity of 0.1 ml min-1. The results indicate that the μDMFC can work steadily with high methanol concentration.

  11. Measurement of Uncertainty for Aqueous Ethanol Wet-Bath Simulator Solutions Used with Evidential Breath Testing Instruments.

    PubMed

    Hwang, Rong-Jen; Beltran, Jada; Rogers, Craig; Barlow, Jeremy; Razatos, Gerasimos

    2016-09-01

    Aqueous ethanol wet-bath simulator solutions are used to perform calibration adjustments, calibration checks, proficiency testing, and inspection of breath alcohol instruments. The Toxicology Bureau of the New Mexico Department of Health has conducted a study to estimate a measurement of uncertainty for the preparation and testing of these wet-bath simulator solutions. The measurand is identified as the mass concentration of ethanol (g/100 mL) determined through dual capillary column headspace gas chromatography with flame ionization detector analysis. Three groups were used in the estimation of the aqueous ethanol wet-bath simulator solutions uncertainty: GC calibration adjustment, GC analytical, and certified reference material. The standard uncertainties for these uncertainty sources were combined using the method of root-sum-squares to give uc = 0.8598%. The combined standard uncertainty was expanded to U = 1.7% to reflect a confidence level of 95% using a coverage factor of 2. This estimation applies to all aqueous ethanol wet-bath simulator solution concentrations produced by this laboratory.

  12. Air-breathing aerospace plane development essential: Hypersonic propulsion flight tests

    NASA Technical Reports Server (NTRS)

    Mehta, Unmeel B.

    1995-01-01

    Hypersonic airbreathing propulsion utilizing scramjets can change transatmospheric accelerators for low earth-to-orbit and return transportation. The value and limitation of ground tests, of flight tests, and of computations are presented, and scramjet development requirements are discussed. It is proposed that near full-scale hypersonic propulsion flight tests are essential for developing computational design technology so that it can be used for designing this system. In order to determine how these objectives should be achieved, some lessons learned from past programs are presented. A conceptual two-stage-to-orbit (TSTO) prototype/experimental aerospace plane is recommended as a means of providing access-to-space and for conducting flight tests.

  13. 32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., administrative actions, and civilian courts. (d) Special rules exist for persons who have hemophilia, other blood-clotting disorders, or any medical or surgical disorder being treated with an anticoagulant. These persons— (1) May refuse a blood extraction test without penalty. (2) Will not be administered a...

  14. 32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., administrative actions, and civilian courts. (d) Special rules exist for persons who have hemophilia, other blood-clotting disorders, or any medical or surgical disorder being treated with an anticoagulant. These persons— (1) May refuse a blood extraction test without penalty. (2) Will not be administered a...

  15. 32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., administrative actions, and civilian courts. (d) Special rules exist for persons who have hemophilia, other blood-clotting disorders, or any medical or surgical disorder being treated with an anticoagulant. These persons— (1) May refuse a blood extraction test without penalty. (2) Will not be administered a...

  16. 32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., administrative actions, and civilian courts. (d) Special rules exist for persons who have hemophilia, other blood-clotting disorders, or any medical or surgical disorder being treated with an anticoagulant. These persons— (1) May refuse a blood extraction test without penalty. (2) Will not be administered a...

  17. 32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., administrative actions, and civilian courts. (d) Special rules exist for persons who have hemophilia, other blood-clotting disorders, or any medical or surgical disorder being treated with an anticoagulant. These persons— (1) May refuse a blood extraction test without penalty. (2) Will not be administered a...

  18. Effective biosynthesis of ethyl (R)-4-chloro-3-hydroxybutanoate by supplementation of l-glutamine, d-xylose and β-cyclodextrin in n-butyl acetate-water media.

    PubMed

    He, Yu-Cai; Tao, Zhi-Cheng; Ding, Yun; Zhang, Dan-Ping; Wu, Yin-Qin; Lu, Yun; Liu, Feng; Xue, Yu-Feng; Wang, Cheng; Xu, Jian-He

    2015-06-10

    To avoid adding NAD(+) and effectively transform ethyl 4-chloro-3-oxobutanoate, the mixture of l-glutamine (200mM) and d-xylose (250mM) was added into in n-butyl acetate-water (10:90, v/v) biphasic system instead of NAD(+) for increasing the biocatalytic efficiency. To further improve the synthesis of optically pure ethyl (R)-4-chloro-3-hydroxybutanoate (>99% ee), β-cyclodextrin was also added into this reaction media, and ethyl (R)-4-chloro-3-hydroxybutanoate (>99% ee) could be effectively synthesized from 800mM ethyl 4-chloro-3-oxobutanoate in the yield of 100% by whole-cells of recombinant E. coli CCZU-A13. Finally, the possible mechanism for improving the reductase activity by supplementation of l-glutamine, d-xylose and β-CD was proposed. In conclusion, this strategy has high potential for the effective biosynthesis of ethyl (R)-4-chloro-3-hydroxybutanoate (>99% ee).

  19. The caffeine breath test and caffeine urinary metabolite ratios in the Michigan cohort exposed to polybrominated biphenyls: A preliminary study

    SciTech Connect

    Lambert, G.H.; Schoeller, D.A.; Kotake, A.N.; Lietz, H. ); Humphrey, H.E.B.; Budd, M. ); Campbell, M.; Kalow, W.; Spielberg, P. )

    1990-11-01

    A field biochemical epidemiology study was conducted using the Michigan cohort consisting of 51 rural residents exposed to polybrominated biphenyls (PBB). The study had three major objectives: (a) to determine the serum half-life of the major PBB congener, hexabromobiphenyl (HBB), in the human, (b) to determine if the PBB-exposed subjects had elevated cytochrome P-450I function as determined by the caffeine breath test (CBT) and the caffeine urinary metabolite ratio (CMR), and (c) to determine the applicability of the CBT and CMR in field studies. PBB serum levels were detected in 36 of the 51 PBB-exposed subjects. The serum half-life of HBB was determined by comparing the current serum HBB values to the subject's previous serum values obtained 5 to 8 years earlier. The median HBB half-life was 12 years (range 4-97 years). The CBT and CMR were elevated in the subjects exposed to PBBs as compared to the values obtained from urban nonsmokers and were similar to those found in adults who smoke. A gender effect was seen in the PBB-exposed subjects. There was a correlation between the CBT and the HBB serum values but not between CMR and HBB serum values. The CBT and CMR were easily conducted in the field and appear to be useful metabolic probes of cytochrome P-450I activity in human environmental toxicology.

  20. Water cooling system for an air-breathing hypersonic test vehicle

    NASA Astrophysics Data System (ADS)

    Petley, Dennis H.; Dziedzic, William M.

    1993-06-01

    This study provides concepts for hypersonic experimental scramjet test vehicles which have low cost and low risk. Cryogenic hydrogen is used as the fuel and coolant. Secondary water cooling systems were designed. Three concepts are shown: an all hydrogen cooling system, a secondary open loop water cooled system, and a secondary closed loop water cooled system. The open loop concept uses high pressure helium (15,000 psi) to drive water through the cooling system while maintaining the pressure in the water tank. The water flows through the turbine side of the turbopump to pump hydrogen fuel. The water is then allowed to vent. In the closed loop concept high pressure, room temperature, compressed liquid water is circulated. In flight water pressure is limited to 6000 psi by venting some of the water. Water is circulated through cooling channels via an ejector which uses high pressure gas to drive a water jet. The cooling systems are presented along with finite difference steady-state and transient analysis results. The results from this study indicate that water used as a secondary coolant can be designed to increase experimental test time, produce minimum venting of fluid and reduce overall development cost.

  1. Water cooling system for an air-breathing hypersonic test vehicle

    NASA Technical Reports Server (NTRS)

    Petley, Dennis H.; Dziedzic, William M.

    1993-01-01

    This study provides concepts for hypersonic experimental scramjet test vehicles which have low cost and low risk. Cryogenic hydrogen is used as the fuel and coolant. Secondary water cooling systems were designed. Three concepts are shown: an all hydrogen cooling system, a secondary open loop water cooled system, and a secondary closed loop water cooled system. The open loop concept uses high pressure helium (15,000 psi) to drive water through the cooling system while maintaining the pressure in the water tank. The water flows through the turbine side of the turbopump to pump hydrogen fuel. The water is then allowed to vent. In the closed loop concept high pressure, room temperature, compressed liquid water is circulated. In flight water pressure is limited to 6000 psi by venting some of the water. Water is circulated through cooling channels via an ejector which uses high pressure gas to drive a water jet. The cooling systems are presented along with finite difference steady-state and transient analysis results. The results from this study indicate that water used as a secondary coolant can be designed to increase experimental test time, produce minimum venting of fluid and reduce overall development cost.

  2. Prognostic value of 13C-phenylalanine breath test on predicting survival in patients with chronic liver failure

    PubMed Central

    Gallardo-Wong, I; Morán, S; Rodríguez-Leal, G; Castañeda-Romero, B; Mera, R; Poo, J; Uribe, M; Dehesa, M

    2007-01-01

    AIM: To evaluate the prognostic value of percentage of 13C-phenylalanine oxidation (13C-PheOx) obtained by 13C-phenylalanine breath test (13C-PheBT) on the survival of patients with chronic liver failure. METHODS: The hepatic function was determined by standard liver blood tests and the percentage of 13C-PheOx in 118 chronic liver failure patients. The follow-up period was of 64 mo. Survival analysis was performed by the Kaplan-Meier method and variables that were significant (P < 0.10) in univariate analysis and subsequently introduced in a multivariate analysis according to the hazard model proposed by Cox. RESULTS: Forty-one patients died due to progressive liver failure during the follow-up period. The probability of survival at 12, 24, 36, 48 and 64 mo was 0.88, 0.78, 0.66, 0.57 and 0.19, respectively. Multivariate analysis demonstrated that Child-Pugh classes, age, creatinine and the percentage of 13C-PheOx (HR 0.338, 95% CI: 0.150-0.762, P = 0.009) were independent predictors of survival. When Child-Pugh classes were replaced by all the parameters of the score, only albumin, bilirubin, creatinine, age and the percentage of 13C-PheOx (HR 0.449, 95% CI: 0.206-0.979, P = 0.034) were found to be independent predictors of survival. CONCLUSION: Percentage of 13C-PheOx obtained by 13C-PheBT is a strong predictor of survival in patients with chronic liver disease. PMID:17729409

  3. The [14C-N-methyl]-erythromycin breath test dosimetry complies with the French regulations for radiation safety.

    PubMed

    Salvat, Cécile; Mouly, Stéphane; Rizzo-Padoin, Nathalie; Knellwolf, Anne-Laure; Simoneau, Guy; Duet, Michèle; Nataf, Valérie; Bailliart, Olivier; Bergmann, Jean-François

    2003-06-01

    The [14C-N-methyl]-erythromycin breath test (14C-ERMBT) is one of the most valuable probes for liver cytochrome P450-3A4 activity in humans. In order to extend the use of this test in France, we herein provide safety data regarding either patient dosimetry or worker exposure to [14C-N-methyl]-erythromycin. In order to determine the maximum radiation exposure for patient and nuclear medicine technician following one intravenous 14C-ERMBT [111 kiloBequerel (kBq)], we have used the dosimetric data gathered in animal studies and extrapolated to humans using a weight-based method, approximate data provided by the French Society of Radioprotection and erythromycin pharmacokinetics in humans, considering always the worst conditions for the patient and worker exposure determination. The radioactivity administered to a patient after one 14C-ERMBT was equal to 108.8 kBq (i.e. 98% of the total radioactivity in the 14C-erythromycin vial) leading to a patient effective dose of 20 microsievert (microSv) and a maximum effective dose after 14CO2 inhalation by the exposed worker of 16 microSv compared with a mean individual annual effective dose from natural and artificial radioactivity exposure of 3500 microSv in France. The 14C-ERMBT is safe and complies with the European regulations regarding the administration of 14C-labelled compounds in humans. It can therefore be used in clinical research in France without any particular safety requirement.

  4. Lactose tolerance tests

    MedlinePlus

    Hydrogen breath test for lactose tolerance ... Two common methods include: Lactose tolerance blood test Hydrogen breath test The hydrogen breath test is the preferred method. It measures the amount of hydrogen in the air you breathe out. ...

  5. A Stable Isotope Breath Test with a Standard Meal for Abnormal Gastric Emptying of Solids in the Clinic and in Research

    PubMed Central

    Szarka, Lawrence A.; Camilleri, Michael; Vella, Adrian; Burton, Duane; Baxter, Kari; Simonson, Julie; Zinsmeister, Alan R.

    2009-01-01

    Aim To validate a [13C]-Spirulina platensis gastric emptying (GE) breath test (GEBT) with a standardized meal. Methods 38 healthy volunteers and 129 patients with clinically suspected delayed GE underwent measurements at 45, 90, 120, 150, 180, and 240 min after a 238 kcal meal labeled test with 100 mg [13C]-Spirulina platensis, and 0.5 mCi 99mTc. We established normal ranges for scintigraphy with this test meal, intra- and inter-individual coefficients of variation (COV) and the ability of the [13C] GEBT breath kPCD (percent dose excreted *1000) values to predict scintigraphic t½, and to categorize GE as delayed, normal or accelerated. Results In health, the 10th and 90th percentile of t½ for scintigraphic GE with this meal are 52 and 86 min; intra-individual COV for scintigraphy and the GEBT were respectively 31% and 27% at 45 min; 17% and 21% at 90 min; 13% and 16% at 120 min; 10% and 13% at 150 min; and 8% and 12% at 180 min. Inter-individual COVs at each time for the [13C] GEBT and scintigraphy were typically ~ 1–4% lower than intra-individual COVs. Individual breath samples at 45, 150 and 180 min predicted GE category: at 80% specificity, 45 and 180 min samples combined were 93% sensitive to identify accelerated GE; 150 and 180 min combined were 89% sensitive for delayed GE. Conclusions [13C]-Spirulina platensis GEBT is as reproducible as scintigraphy; imprecision with both tests reflects physiologic variation. Using 4 breath samples, this method with an off-the-shelf meal is valid to assess GE in clinic and in research. PMID:18406670

  6. Relationship between Helicobacter pylori infection estimated by 14C-urea breath test and gender, blood groups and Rhesus factor.

    PubMed

    Petrović, Milorad; Artiko, Vera; Novosel, Slavica; Ille, Tanja; Šobić-Šaranović, Dragana; Pavlović, Smiljana; Jakšić, Emilija; Stojković, Mirjana; Antić, Andrija; Obradović, Vladimir

    2011-01-01

    The aim of this study was the detection of helicobacter pylori (HP) infection and estimation of this infection relationship with age, gender, blood groups and Rhesus factor, as well as the assessment of the accuracy of the method. A total of 227 patients with gastritis were examined. Blood ABO groups and Rh positivity were determined using standard tests. Infection by HP was proved by (14)C-urea breath test and gastric biopsy. Patients were aged 20-81 years (X=51.7 years) and the presence of HP was not related to the age (P>0.05). From the total number of patients, 25/69 males and 68/158 females were HP positive. There was no significant difference between genders and HP infection (P>0.05). From the 227 investigated patients, 69 (30%) belonged to blood group O, 96 (42%) to A, 40 (18%) to B and 22 (10%) to AB. HP was detected in 27/69 patients with blood group O, 45/96 patients with blood group A, 16/40 patients with blood group B and 5/22 patients with blood group AB. There was no statistically significant difference (P>0.05) in the incidence of HP infection between these groups (proving that HP infection did not depend upon the blood groups). Also, there was no significant correlation between the presence of particular blood group in HP+ patients related to the reported frequency of the blood groups in Serbian population (0--38%, A--42%, B--15%, AB--5%). HP was found in 16/36 Rh- and in 77/191 Rh+ patients without statistical difference (P>0.05). Also, there was no significant correlation of the presence of the Rh factor in the HP positive patients to the frequency of the Rh factor in the Serbian population (84% Rh+ and 16% Rh-). The basic value of the HP+ test was slightly, but not significantly lower in comparison to the HP- patients (P>0.05). On the contrary, test values showed a highly significant difference (P<0.01) in HP+ and HP- patients. In conclusion, in adults HP infection does not depend upon the patient's age, gender, blood group type or Rh factor. In

  7. Determination of rifaximin treatment period according to lactulose breath test values in nonconstipated irritable bowel syndrome subjects.

    PubMed

    Bae, Suhyun; Lee, Kwang Jae; Kim, Young-Sang; Kim, Kyu-Nam

    2015-06-01

    Small intestinal bacterial overgrowth (SIBO) can partly explain irritable bowel syndrome (IBS), and rifaximin has been observed to improve abdominal symptoms in nonconstipated IBS patients. However, there are few reports on the association of the rifaximin treatment periods with the results of a lactulose breath test (LBT). Therefore, we performed a retrospective review of patient charts to investigate the relation between the rifaximin treatment periods with LBT results in nonconstipated IBS patients. We also evaluated the time to achieve a symptomatic improvement in the IBS patients as compared to the changes in the LBT. We reviewed the charts for patients who showed IBS symptoms with documented positive results for LBT during their initial visit and who had a follow-up LBT after treatment with rifaximin. The LBT values were compared to the subjects' symptom scores. A total of 102 subjects had a follow-up LBT to assess LBT normalization. The subjects were divided into groups according to treatment periods of 4 weeks (n = 36), 8 weeks (n = 43), and 12 weeks (n = 23). The groups with a longer treatment exhibited an increase in the hydrogen gas value at 90 min and its sum during 90 min at the initial LBT. There were significant differences in hydrogen gas value at 90 min and in its sum during 90 min at the initial LBT between the groups treated for 4 and 12 weeks. The most significant treatment response was observed during the first 4 weeks for all treatment groups. Symptomatic improvement occurred earlier than LBT normalization in the treatment period over 4 weeks. The results indicate that different rifaximin treatment periods are needed in accordance with LBT levels to effectively eradicate SIBO. PMID:26028929

  8. Syntheses of 2-keto-3-deoxy-D-xylonate and 2-keto-3-deoxy-L-arabinonate as stereochemical probes for demonstrating the metabolic promiscuity of Sulfolobus solfataricus towards D-xylose and L-arabinose.

    PubMed

    Archer, Robert M; Royer, Sylvain F; Mahy, William; Winn, Caroline L; Danson, Michael J; Bull, Steven D

    2013-02-18

    Practical syntheses of 2-keto-3-deoxy-D-xylonate (D-KDX) and 2-keto-3-deoxy-L-arabinonate (L-KDA) that rely on reaction of the anion of ethyl 2-[(tert-butyldimethylsilyl)oxy]-2-(dimethoxy phosphoryl) acetate with enantiopure glyceraldehyde acetonide, followed by global deprotection of the resultant O-silyl-enol esters, have been developed. This has enabled us to confirm that a 2-keto-3-deoxy-D-gluconate aldolase from the archaeon Sulfolobus solfataricus demonstrates good activity for catalysis of the retro-aldol cleavage of both these enantiomers to afford pyruvate and glycolaldehyde. The stereochemical promiscuity of this aldolase towards these enantiomeric aldol substrates confirms that this organism employs a metabolically promiscuous pathway to catabolise the C5-sugars D-xylose and L-arabinose.

  9. Validation of the string test for the recovery of Helicobacter pylori from gastric secretions and correlation of its results with urea breath test results, serology, and gastric pH levels.

    PubMed

    Torres, J; Camorlinga, M; Pérez-Peréz, G; Gonzalez, G; Muñoz, O

    2001-04-01

    The efficacy of the string culture test to isolate Helicobacter pylori from gastric secretions of 28 volunteers was studied. With the urea breath test (UBT) as the "gold standard," the string culture test showed a sensitivity of 75% and a specificity of 100%. The results of string culture did not correlate with the UBT results, with serum antibody levels, or with the pH levels of gastric secretions.

  10. Validation of the String Test for the Recovery of Helicobacter pylori from Gastric Secretions and Correlation of Its Results with Urea Breath Test Results, Serology, and Gastric pH Levels

    PubMed Central

    Torres, Javier; Camorlinga, Margarita; Pérez-Peréz, Guillermo; Gonzalez, Gerardo; Muñoz, Onofre

    2001-01-01

    The efficacy of the string culture test to isolate Helicobacter pylori from gastric secretions of 28 volunteers was studied. With the urea breath test (UBT) as the “gold standard,” the string culture test showed a sensitivity of 75% and a specificity of 100%. The results of string culture did not correlate with the UBT results, with serum antibody levels, or with the pH levels of gastric secretions. PMID:11283108

  11. What Controls Your Breathing?

    MedlinePlus

    ... To a limited degree, you can change your breathing rate, such as by breathing faster or holding your ... oxygen levels in your blood and change your breathing rate as needed. Sensors in the airways detect lung ...

  12. Breath-Holding Spells

    MedlinePlus

    ... less than a minute before a child regains consciousness and resumes breathing normally. Breath-holding spells can ... spells cause kids to stop breathing and lose consciousness for up to a minute. In the most ...

  13. Psychometric evaluation of the COPD assessment test: data from the BREATHE study in the Middle East and North Africa region.

    PubMed

    Jones, Paul W; Shahrour, Naem; Nejjari, Chakib; Lahlou, Aicha; Doble, Adam; Rashid, Nauman; El Hasnaoui, Abdelkader

    2012-12-01

    The objective of this study was to assess the validity and performance of the Arabic and Turkish versions of the COPD Assessment Test (CAT) for evaluating the severity and impact of COPD symptoms. The data were obtained from the BREATHE study in the Middle East and North Africa region, a large general population survey of COPD conducted in ten countries of the region (Algeria, Egypt, Jordan, Lebanon, Morocco, Saudi Arabia, Syria, Tunisia, Turkey and United Arab Emirates), using a standardised methodology. A total of 62,086 subjects were screened, of whom a random sample of 5,681 subjects were administered the CAT by telephone. 5,639 evaluable questionnaires were recovered, representing a completion rate of 99%. In addition, the CAT was administered to an additional 833 subjects fulfilling the epidemiological diagnostic criteria for COPD. Mean scores in the general population were 6.99 ± 6.91 for the Arabic version and 9.88 ± 9.04 for the Turkish version. In patients with COPD, mean scores were 16.2 ± 9.1 and 20.9 ± 10.2 respectively. Scores were consistently higher in smokers than in non-smokers. In the general population, the proportion of respondents fulfilling criteria for COPD rose with higher CAT scores, and particularly above the 80th percentile, where 63% of COPD cases were to be found. This suggests that the CAT may be useful as a case-finding tool in the general population. In the COPD population, healthcare resource consumption rose linearly with CAT score above a threshold score of twenty, arguing in favour of the good criterion validity of the CAT. The internal consistency of the CAT was high (Cronbach's α 0.85 for the Arabic and 0.86 for the Turkish versions) and the factorial structure was unidimensional. In conclusion, this study performed in Arabic and Turkish speaking populations confirms the utility and validity of the CAT as a simple tool to collect data on the severity and impact of COPD symptoms, and suggests that it may potentially be

  14. Evaluation of CYP2D6 enzyme activity using a Dextromethorphan Breath Test in Women Receiving Adjuvant Tamoxifen

    PubMed Central

    Safgren, Stephanie L.; Suman, Vera J.; Kosel, Matthew L.; Gilbert, Judith A; Buhrow, Sarah A.; Black, John L.; Northfelt, Donald W.; Modak, Anil S.; Rosen, David; Ingle, James N.; Ames, Matthew M.; Reid, Joel M.; Goetz, Matthew P.

    2015-01-01

    Background In tamoxifen-treated patients, breast cancer recurrence differs according to CYP2D6 genotype and endoxifen steady state concentrations (Endx Css). The 13Cdextromethorphan breath test (DM-BT), labeled with 13C at the O-CH3 moiety, measures CYP2D6 enzyme activity. We sought to examine the ability of the DM-BT to identify known CYP2D6 genotypic poor metabolizers and examine the correlation between DMBT and Endx Css. Methods DM-BT and tamoxifen pharmacokinetics were obtained at baseline (b), 3 month (3m) and 6 months (6m) following tamoxifen initiation. Potent CYP2D6 inhibitors were prohibited. The correlation between bDM-BT with CYP2D6 genotype and Endx Css was determined. The association between bDM-BT (where values ≤0.9 is an indicator of poor in vivo CYP2D6 metabolism) and Endx Css (using values ≤ 11.2 known to be associated with poorer recurrence free survival) was explored. Results 91 patients were enrolled and 77 were eligible. CYP2D6 genotype was positively correlated with b, 3m and 6m DMBT (r ranging from 0.457-0. 60 p < 0.001). Both CYP2D6 genotype (r = 0.47; 0.56, p <.0001), and bDM-BT (r=0.60; 0.54; p<.001) were associated with 3m and 6m Endx Css respectively. Seven of 9 patients (78%) with low (≤11.2 nM) 3m Endx Css also had low DM-BT (≤0.9) including 2/2 CYP2D6 PM/PM and 5/5 IM/PM. In contrast, 1 of 48 pts (2%) with a low DM-BT had Endx Css > 11.2 nM. Conclusions In patients not taking potent CYP2D6 inhibitors, DM-BT was associated with CYP2D6 genotype and 3m and 6 m Endx Css but did not provide better discrimination of Endx Css compared to CYP2D6 genotype alone. Further studies are needed to identify additional factors which alter Endx Css. PMID:25714002

  15. Comparison of the 13C-urea breath test and the endoscopic phenol red mucosal pH test in the quantification of Helicobacter pylori infection loading

    PubMed Central

    Cho, Young-Seok; Jang, Se Na; Kim, Jin-Soo; Son, Hye Suk; Kim, Hyung-Keun; Kim, Byung-Wook; Han, Sok-Won; Choi, Kyu-Yong; Lee, Hae Kyung; Chang, Eun Deok

    2008-01-01

    Background/Aims The 13C-urea breath test (UBT) is a semiquantitative test for measuring Helicobacter pylori infection loading. H. pylori produces ammonia, which elevates the pH of the gastric mucosa and is detectable via endoscopy using a phenol red indicator. We evaluated whether this test could be used to diagnose H. pylori infection and whether phenol red staining was correlated with 13C-UBT results. Methods One hundred and twenty-three patients participated. The UBT was performed after ingestion of a capsule containing urea. A change in 13C-UBT >2‰ was selected as the cutoff value for diagnosing infection. After spraying evenly with a 0.1% phenol red solution, the pH of the gastric mucosal surface was measured using an antimony electrode through the biopsy channel. Results The pH of stained mucosa (6.9±0.4) was significantly higher than that of unstained mucosa (1.9±0.8; p<0.001), and the H. pylori detection rate confirmed via histology was higher in stained versus unstained mucosa (p<0.01). Extensive mucosal staining resulted in a higher detection rate (p<0.001). The UBT produced results were very similar to those obtained via histological detection in stained mucosa (p<0.001). The extent of staining, expressed as a staining score, was positively correlated with the change in 13C-UBT (r=0.426, p<0.001). A significant correlation was also observed between the histologically determined H. pylori density and 13C-UBT results (r=0.674, p<0.001). Conclusions H. pylori infection elevates gastric mucosal surface pH, and endoscopic phenol red staining may be an alternative method for the diagnosis of H. pylori infection. PMID:18787366

  16. Breathing difficulty - lying down

    MedlinePlus

    ... Paroxysmal nocturnal dyspnea; PND; Difficulty breathing while lying down; Orthopnea ... does not directly cause difficulty breathing while lying down but often worsens other conditions that lead to ...

  17. Analysis of Exhaled Breath for Disease Detection

    NASA Astrophysics Data System (ADS)

    Amann, Anton; Miekisch, Wolfram; Schubert, Jochen; Buszewski, Bogusław; Ligor, Tomasz; Jezierski, Tadeusz; Pleil, Joachim; Risby, Terence

    2014-06-01

    Breath analysis is a young field of research with great clinical potential. As a result of this interest, researchers have developed new analytical techniques that permit real-time analysis of exhaled breath with breath-to-breath resolution in addition to the conventional central laboratory methods using gas chromatography-mass spectrometry. Breath tests are based on endogenously produced volatiles, metabolites of ingested precursors, metabolites produced by bacteria in the gut or the airways, or volatiles appearing after environmental exposure. The composition of exhaled breath may contain valuable information for patients presenting with asthma, renal and liver diseases, lung cancer, chronic obstructive pulmonary disease, inflammatory lung disease, or metabolic disorders. In addition, oxidative stress status may be monitored via volatile products of lipid peroxidation. Measurement of enzyme activity provides phenotypic information important in personalized medicine, whereas breath measurements provide insight into perturbations of the human exposome and can be interpreted as preclinical signals of adverse outcome pathways.

  18. SU-D-BRE-01: A Realistic Breathing Phantom of the Thorax for Testing New Motion Mitigation Techniques with Scanning Proton Therapy

    SciTech Connect

    Perrin, R; Peroni, M; Bernatowicz, K; Zakova, M; Knopf, A; Safai, S; Parkel, T

    2014-06-01

    Purpose: A prototype breathing phantom (named LuCa) has been developed which simulates the anatomy and motion of a patient thorax.In this work, we describe the results of the first commissioning tests with LuCa. Methods: The phantom provides a close representation of the human thorax. The lungs,contained within a tissue-equivalent ribcage and skin,are made from a polymer foam,which is inflated and deflated using a custommade ventilator. A tumor is simulated using a wooden ball with cutplanes for placing GafChromic films. The ventilator,controlled with Labview software,simulates a full range of breathing motion types.Commissioning tests were performed to assess its performance using imaging (CT and radiographic) and film dosimetry as follows:i)maximum Tumor excursion at acceptable pressure ranges, ii)tumor Motion repeatability between breathing periods,iii)reproducibility between measurement days,iv)tumor-to-surface motion correlation and v)reproducibility of film positioning in phantom. Results: The phantom can generate repeatable motion patterns with sin{sup 4},sin,breath-hold (tumor amplitude repeatability <0.5mm over 10min),aswell as patient-specific motion types. Maximum excursions of the tumor are 20mm and 14mm for the large and small tumor inserts respectively. Amplitude reproducibility (Coefficient of Variation) averaged at 16% for the workable pressure range over 2 months. Good correlation between tumor and surface motion was found with R{sup 2}=0.92. Reproducibility of film positioning within the thorax was within 0.9mm, and maximum 3° error from the coronal plane. Film measurements revealed that the film repositioning error yields relative errors in the mean dose over the planned target volume (PTV) of up to 2.5% and 4.5% for films at the center and on the edge of the PTV respectively. Conclusion: Commissioning tests have shown that the LuCa phantom can produce tumor motion with excellent repeatability. However,a poorer performance in reproducibility of

  19. 13C-tryptophan breath test detects increased catabolic turnover of tryptophan along the kynurenine pathway in patients with major depressive disorder

    PubMed Central

    Teraishi, Toshiya; Hori, Hiroaki; Sasayama, Daimei; Matsuo, Junko; Ogawa, Shintaro; Ota, Miho; Hattori, Kotaro; Kajiwara, Masahiro; Higuchi, Teruhiko; Kunugi, Hiroshi

    2015-01-01

    Altered tryptophan–kynurenine (KYN) metabolism has been implicated in major depressive disorder (MDD). The l-[1-13C]tryptophan breath test (13C-TBT) is a noninvasive, stable-isotope tracer method in which exhaled 13CO2 is attributable to tryptophan catabolism via the KYN pathway. We included 18 patients with MDD (DSM-IV) and 24 age- and sex-matched controls. 13C-tryptophan (150 mg) was orally administered and the 13CO2/12CO2 ratio in the breath was monitored for 180 min. The cumulative recovery rate during the 180-min test (CRR0–180; %), area under the Δ13CO2-time curve (AUC; %*min), and the maximal Δ13CO2 (Cmax; %) were significantly higher in patients with MDD than in the controls (p = 0.004, p = 0.008, and p = 0.002, respectively). Plasma tryptophan concentrations correlated negatively with Cmax in both the patients and controls (p = 0.020 and p = 0.034, respectively). Our results suggest that the 13C-TBT could be a novel biomarker for detecting a subgroup of MDD with increased tryptophan–KYN metabolism. PMID:26524975

  20. Helicobacter pylori Test

    MedlinePlus

    ... pylori stool antigen test; H. pylori breath test; Urea breath test; CLO test; Rapid urease test (RUT) ... of H. pylori antigen in a stool sample Urea breath test A person drinks a liquid containing ...

  1. Use of the Biphasic 13C-Sucrose/Glucose Breath Test to Assess Sucrose Maldigestion in Adults with Functional Bowel Disorders

    PubMed Central

    Balesh, Albert M.; Shelby, Harold T.

    2016-01-01

    Sucrase insufficiency has been observed in children with of functional bowel disorders (FBD) and symptoms of dietary carbohydrate intolerance may be indistinguishable from those of FBD. A two-phase 13C-sucrose/13C-glucose breath test (13C-S/GBT) was used to assess sucrase activity because disaccharidase assays are seldom performed in adults. When 13C-sucrose is hydrolyzed to liberate monosaccharides, oxidation to 13CO2 is a proportional indicator of sucrase activity. Subsequently, 13C-glucose oxidation rate was determined after a secondary substrate ingestion (superdose) to adjust for individual habitus effects (Phase II). 13CO2 enrichment recovery ratio from 13C-sucrose and secondary 13C-glucose loads reflect the individualized sucrase activity [Coefficient of Glucose Oxidation for Sucrose (CGO-S)]. To determine if sucrase insufficiency could be a factor in FBD, 13C-S/GBT was validated using subjects with known sucrase gene mutation status by comparing 13CO2-breath enrichment with plasma 13C-glucose enrichment. 13C-S/GBT was used to assess sucrose digestion in FBD patients and asymptomatic controls. 13CO2-breath enrichment correlated with the appearance of 13C-sucrose-derived glucose in plasma (r2 = 0.80). Mean, control group CGO-S-enrichment outcomes were 1.01 at 60′, 0.92 at 75′, and 0.96 at mean 60′–75′ with normal CGO-S defined as >0.85 (95% C.I.). In contrast, FBD patients demonstrated lower CGO-S values of 0.77 at 60′, 0.77 at 75′, and 0.76 at mean 60′–75′ (Chi Square: 6.55; p < 0.01), which points to sucrose maldigestion as a cause of FBD. PMID:27579322

  2. Use of the Biphasic (13)C-Sucrose/Glucose Breath Test to Assess Sucrose Maldigestion in Adults with Functional Bowel Disorders.

    PubMed

    Opekun, Antone R; Balesh, Albert M; Shelby, Harold T

    2016-01-01

    Sucrase insufficiency has been observed in children with of functional bowel disorders (FBD) and symptoms of dietary carbohydrate intolerance may be indistinguishable from those of FBD. A two-phase (13)C-sucrose/(13)C-glucose breath test ((13)C-S/GBT) was used to assess sucrase activity because disaccharidase assays are seldom performed in adults. When (13)C-sucrose is hydrolyzed to liberate monosaccharides, oxidation to (13)CO2 is a proportional indicator of sucrase activity. Subsequently, (13)C-glucose oxidation rate was determined after a secondary substrate ingestion (superdose) to adjust for individual habitus effects (Phase II). (13)CO2 enrichment recovery ratio from (13)C-sucrose and secondary (13)C-glucose loads reflect the individualized sucrase activity [Coefficient of Glucose Oxidation for Sucrose (CGO-S)]. To determine if sucrase insufficiency could be a factor in FBD, (13)C-S/GBT was validated using subjects with known sucrase gene mutation status by comparing (13)CO2-breath enrichment with plasma (13)C-glucose enrichment. (13)C-S/GBT was used to assess sucrose digestion in FBD patients and asymptomatic controls. (13)CO2-breath enrichment correlated with the appearance of (13)C-sucrose-derived glucose in plasma (r (2) = 0.80). Mean, control group CGO-S-enrichment outcomes were 1.01 at 60', 0.92 at 75', and 0.96 at mean 60'-75' with normal CGO-S defined as >0.85 (95% C.I.). In contrast, FBD patients demonstrated lower CGO-S values of 0.77 at 60', 0.77 at 75', and 0.76 at mean 60'-75' (Chi Square: 6.55; p < 0.01), which points to sucrose maldigestion as a cause of FBD. PMID:27579322

  3. A cohort study to identify simple clinical tests for chronic respiratory failure in obese patients with sleep-disordered breathing

    PubMed Central

    Mandal, S; Suh, E S; Boleat, E; Asher, W; Kamalanathan, M; Lee, K; Douiri, A; Murphy, P B; Steier, J; Hart, N

    2014-01-01

    Background Chronic respiratory failure complicating sleep-disordered breathing in obese patients has important adverse clinical implications in terms of morbidity, mortality and healthcare utilisation. Screening strategies are essential to identify obese patients with chronic respiratory failure. Method Prospective data were collected from patients with obesity-related sleep-disordered breathing admitted for respiratory assessment at a UK national sleep and ventilation centre. Hypercapnia was defined as an arterial partial pressure of carbon dioxide of >6kPa. Results 245 obese patients (56±13 years) with a body mass index of 48±12 kg/m2, forced vital capacity (FVC) of 2.1±1.1 L, daytime oximetry (SpO2) of 91±6% and abnormal overnight oximetry were included in the analysis. Receiver operator curve analysis for the whole group showed that an FVC ≤3 L had a sensitivity of 90% and a specificity of 41% in predicting hypercapnia, and an SpO2 ≤95% had a sensitivity of 83% and a specificity of 63% in predicting hypercapnia. Gender differences were observed and receiver operator curve analysis demonstrated ‘cut-offs’ for (1) SpO2 of ≤95% for men and ≤93% for women and (2) FVC of ≤3.5 L for men and ≤2.3 L for women, in predicting hypercapnia. Conclusions The measurement of FVC and clinic SpO2 in obese patients with abnormal overnight limited respiratory studies predicted hypercapnia. This may have clinical utility in stratifying patients attending sleep clinics. PMID:25478174

  4. The influence of Aspergillus niger transcription factors AraR and XlnR in the gene expression during growth in D-xylose, L-arabinose and steam-exploded sugarcane bagasse.

    PubMed

    de Souza, Wagner Rodrigo; Maitan-Alfenas, Gabriela Piccolo; de Gouvêa, Paula Fagundes; Brown, Neil Andrew; Savoldi, Marcela; Battaglia, Evy; Goldman, Maria Helena S; de Vries, Ronald P; Goldman, Gustavo Henrique

    2013-11-01

    The interest in the conversion of plant biomass to renewable fuels such as bioethanol has led to an increased investigation into the processes regulating biomass saccharification. The filamentous fungus Aspergillus niger is an important microorganism capable of producing a wide variety of plant biomass degrading enzymes. In A. niger the transcriptional activator XlnR and its close homolog, AraR, controls the main (hemi-)cellulolytic system responsible for plant polysaccharide degradation. Sugarcane is used worldwide as a feedstock for sugar and ethanol production, while the lignocellulosic residual bagasse can be used in different industrial applications, including ethanol production. The use of pentose sugars from hemicelluloses represents an opportunity to further increase production efficiencies. In the present study, we describe a global gene expression analysis of A. niger XlnR- and AraR-deficient mutant strains, grown on a D-xylose/L-arabinose monosaccharide mixture and steam-exploded sugarcane bagasse. Different gene sets of CAZy enzymes and sugar transporters were shown to be individually or dually regulated by XlnR and AraR, with XlnR appearing to be the major regulator on complex polysaccharides. Our study contributes to understanding of the complex regulatory mechanisms responsible for plant polysaccharide-degrading gene expression, and opens new possibilities for the engineering of fungi able to produce more efficient enzymatic cocktails to be used in biofuel production.

  5. News from the Breath Analysis Summit 2011.

    PubMed

    Corradi, Massimo; Mutti, Antonio

    2012-05-23

    This special section highlights some of the important work presented at the Breath Analysis Summit 2011, which was held in Parma (Italy) from 11 to 14 September 2011. The meeting, which was jointly organized by the International Association for Breath Research and the University of Parma, was attended by more than 250 delegates from 33 countries, and offered 34 invited lectures and 64 unsolicited scientific contributions. The summit was organized to provide a forum to scientists, engineers and clinicians to present their latest findings and to meet industry executives and entrepreneurs to discuss key trends, future directions and technologies available for breath analysis. A major focus was on nitric oxide, exhaled breath condensate, electronic nose, mass spectrometry and newer sensor technologies. Medical applications ranged from asthma and other respiratory diseases to gastrointestinal disease, occupational diseases, critical care and cancer. Most people identify breath tests with breathalysers used by police to estimate ethanol concentration in blood. However, breath testing has far more sophisticated applications. Breath analysis is rapidly evolving as a new frontier in medical testing for disease states in the lung and beyond. Every individual has a breath fingerprint-or 'breathprint'-that can provide useful information about his or her state of health. This breathprint comprises the many thousands of molecules that are expelled with each breath we exhale. Breath research in the past few years has uncovered the scientific and molecular basis for such clinical observations. Relying on mass spectrometry, we have been able to identify many such unique substances in exhaled breath, including gases, such as nitric oxide (NO) and carbon monoxide (CO), and a wide array of volatile organic compounds. Exhaled breath also carries aerosolized droplets that can be collected as an exhaled breath condensate that contains endogenously produced non-volatile compounds. Breath

  6. 13C-methacetin breath test: isotope-selective nondispersive infrared spectrometry in comparison to isotope ratio mass spectrometry in volunteers and patients with liver cirrhosis.

    PubMed

    Adamek, R J; Goetze, O; Boedeker, C; Pfaffenbach, B; Luypaerts, A; Geypens, B

    1999-12-01

    The 13C-methacetin breath test (MBT) has been proposed for the noninvasive evaluation of the hepatic mixed function oxidase activity. Up to now, stable isotope analysis of carbon dioxide of the MBT has been carried out with isotope ratio mass spectrometry (IRMS). The aim of the present study was to test a recently developed isotope-selective nondispersive infrared spectrometer (NDIRS) in comparison to IRMS in healthy volunteers and patients with liver cirrhosis. Ten healthy volunteers (range 22 to 76 years) and ten patients with histologically proven liver cirrhosis (range 47 to 71 years; Child Pugh score A = 5, B = 3, C = 2) were studied. After an overnight fast each subject received 2 mg/kg BW of 13C-methacetin dissolved in 100 ml of tea. Breath samples were obtained before substrate administration and after 5, 10, 15, 20, 30, 40, 50, 60, 80, 100, 120, 150, 180 min. The 13C/12C-ratio was analyzed in each breath sample both by NDIRS (IRIS, Wagner Analysen Technik, Worpswede, Germany) and CF-IRMS (ABCA, Europa Scientific, Crewe, UK). Results were expressed as delta over baseline (DOB [/1000]) and as cumulative percentage doses of 13C recovered (cPDR [%]) at each time interval. Correlations between IRMS and NDIRS were tested by linear regression correlation. For measuring agreement an Altman-Bland-plot was performed. Applying correlation analysis a linear correlation was found (DOB: y = 1.068 +/- 0.0012.x + 2.088 +/- 0.2126, r = 0.98, p < 0.0001; cPDR: y = 1.148 +/- 0.0109.x + 0.569 +/- 0.172; r = 0.99, p < 0.0001). For DOB the mean difference (d) was 2.9/1000 and the standard deviation (SD) of the difference was 2.7/1000. The limits of agreement (d +/- SD) were -2.5/1000 and 8.3/1000. The comparison of DOB- and cPDR-values by NDIRS and IRMS shows a high linear correlation. However, the distance of the limits of agreement is wide. Consequently, the validity of the MBT could be influenced which could make MBT by NDIRS unprecise for exact evaluation of hepatocellular

  7. Rapid CO breath test screening of drugs for protective effects on ribavirin-induced hemolysis in a rabbit model: a pilot study.

    PubMed

    Ma, Yong-Jian; Zhang, Hou-De; Wu, Chuang-Hong; Zhu, Guo-Liang; Ji, Yong-Qiang; Huang, Jia-Liang; Du, Li-Tao; Cao, Ping; Zang, De-Yue; Ji, Kun-Mei

    2016-01-01

    Hemolytic anemia is a major side effect of ribavirin antiviral treatment for chronic hepatitis C. Ribavirin dose reduction may compromise the antiviral response and erythropoietin can take several weeks to alleviate anemia. The purpose of the present study was to screen potentially protective drugs against ribavirin-induced hemolytic anemia in a rabbit model, using our modified CO breath test for measuring erythrocyte (RBC) lifespan, the gold standard diagnostic index of hemolysis. Fifteen rabbits were divided randomly into five groups (N  =  3/group): one vehicle control group, one ribavirin (only)-treated (RBV) group, and three groups initially treated with ribavirin only, followed by a combination of ribavirin with prednisone (RBV  +  Pred), polyene phosphatidyl choline (RBV  +  PPC), or reduced glutathione (RBV  +  GSH). RBC lifespan was calculated from accumulated CO measured in a closed rebreath apparatus, blood volume measured by the Evan's blue dye (EBD) dilution test, and hemoglobin concentration data. The RBC lifespan was normal in the vehicle control group (44-60 d), but reduced significantly in all of the ribavirin-treated groups before the addition of screened drugs (17-35 d). RBC lifespan rebounded significantly with the addition of glutathione, but not with the addition of prednisone or polyene phosphatidyl choline. A similar overall drug effect pattern was seen in the hemoglobin concentration and reticulocyte count data. In conclusion, the results of this pilot study indicate that reduced glutathione can attenuate ribavirin-induced hemolytic anemia, and that the RBC lifespan measured with our modified rapid CO breath test is feasible and reliable for use in animal studies. PMID:27506143

  8. Rapid CO breath test screening of drugs for protective effects on ribavirin-induced hemolysis in a rabbit model: a pilot study.

    PubMed

    Ma, Yong-Jian; Zhang, Hou-De; Wu, Chuang-Hong; Zhu, Guo-Liang; Ji, Yong-Qiang; Huang, Jia-Liang; Du, Li-Tao; Cao, Ping; Zang, De-Yue; Ji, Kun-Mei

    2016-08-10

    Hemolytic anemia is a major side effect of ribavirin antiviral treatment for chronic hepatitis C. Ribavirin dose reduction may compromise the antiviral response and erythropoietin can take several weeks to alleviate anemia. The purpose of the present study was to screen potentially protective drugs against ribavirin-induced hemolytic anemia in a rabbit model, using our modified CO breath test for measuring erythrocyte (RBC) lifespan, the gold standard diagnostic index of hemolysis. Fifteen rabbits were divided randomly into five groups (N  =  3/group): one vehicle control group, one ribavirin (only)-treated (RBV) group, and three groups initially treated with ribavirin only, followed by a combination of ribavirin with prednisone (RBV  +  Pred), polyene phosphatidyl choline (RBV  +  PPC), or reduced glutathione (RBV  +  GSH). RBC lifespan was calculated from accumulated CO measured in a closed rebreath apparatus, blood volume measured by the Evan's blue dye (EBD) dilution test, and hemoglobin concentration data. The RBC lifespan was normal in the vehicle control group (44-60 d), but reduced significantly in all of the ribavirin-treated groups before the addition of screened drugs (17-35 d). RBC lifespan rebounded significantly with the addition of glutathione, but not with the addition of prednisone or polyene phosphatidyl choline. A similar overall drug effect pattern was seen in the hemoglobin concentration and reticulocyte count data. In conclusion, the results of this pilot study indicate that reduced glutathione can attenuate ribavirin-induced hemolytic anemia, and that the RBC lifespan measured with our modified rapid CO breath test is feasible and reliable for use in animal studies.

  9. Minimizing Shortness of Breath

    MedlinePlus

    ... Top Doctors in the Nation Departments & Divisions Home Health Insights Stress & Relaxation Breathing and Relaxation Minimizing Shortness of Breath ... Management Assess Your Stress Coping Strategies Identifying ... & Programs Health Insights Doctors & Departments Research & Science Education & Training Make ...

  10. Breathing and Relaxation

    MedlinePlus

    ... Top Doctors in the Nation Departments & Divisions Home Health Insights Stress & Relaxation Breathing and Relaxation Breathing and Relaxation Make ... Management Assess Your Stress Coping Strategies Identifying ... & Programs Health Insights Doctors & Departments Research & Science Education & Training Make ...

  11. NASA firefighters breathing system program report

    NASA Technical Reports Server (NTRS)

    Wood, W. B.

    1977-01-01

    Because of the rising incidence of respiratory injury to firefighters, local governments expressed the need for improved breathing apparatus. A review of the NASA firefighters breathing system program, including concept definition, design, development, regulatory agency approval, in-house testing, and program conclusion is presented.

  12. Prevalence of Helicobacter Pylori Infection in School and Pre-School Aged Children with C-14 Urea Breath Test and the Association with Familial and Environmental Factors

    PubMed Central

    Çınar, Alev; Sadıç, Murat; İkbal Atılgan, Hasan; Baskın, Aylin; Koca, Gökhan; Demirel, Koray; Korkmaz, Meliha

    2015-01-01

    Objective: To investigate the prevalence of Helicobacter pylori (Hp) infection in pre-school and school age children with C-14 urea breath test, and to explore its association with age and socioeconomic factors in Turkey. Methods: Hp infection status was determined by using Urea Breath Test (UBT). Patients who had previous gastric surgery, Hp eradication treatment or equivocal UBT results were excluded. A questionnaire was administered to elicit information on gender, age, ABO/Rh blood group type, presence of gastric disease in the family, domestic animal in the household, and treatment for idiopathic Iron Deficiency Anemia (IDA). Results: This retrospective study included 500 pediatric patients (179 boys, 321 girls, mean age 10.7±4.3 years) of whom 62 (12.4%) were aged ≤6 years and 438 (87.6%) were aged 7 to 16 years. Helicobacter pylori (Hp) was positive in 245 (49%) cases. In the pre-school age group, 21/62 cases (34%) had positive UBT while in the school age group 224/438 children (51%) had positive UBT. A family history of dyspepsia and pet ownership were not associated with Hp positivity. Hp positive 76 (29.8%) children were on IDA treatment but this was not statistically significant. Conclusion: The Hp infection positivity rate was 49% in the pediatric age study group. The positivity rate was significantly lower at preschool age than school age, and it increased with age. There was no association with gender, ABO/Rh blood groups, presence of domestic pets, IDA, or history of gastric disease in the family. PMID:26316471

  13. The non-invasive 13C-methionine breath test detects hepatic mitochondrial dysfunction as a marker of disease activity in non-alcoholic steatohepatitis

    PubMed Central

    2011-01-01

    Introduction Mitochondrial dysfunction plays a central role in the general pathogenesis of non-alcoholic fatty liver disease (NAFLD), increasing the risk of developing steatosis and subsequent hepatocellular inflammation. We aimed to assess hepatic mitochondrial function by a non-invasive 13C-methionine breath test (MeBT) in patients with histologically proven NAFLD. Methods 118 NAFLD-patients and 18 healthy controls were examined by MeBT. Liver biopsy specimens were evaluated according to the NASH scoring system. Results Higher grades of NASH activity and fibrosis were independently associated with a significant decrease in cumulative 13C-exhalation (expressed as cPDR(%)). cPDR1.5h was markedly declined in patients with NASH and NASH cirrhosis compared to patients with simple steatosis or borderline diagnosis (cPDR1.5h: 3.24 ± 1.12% and 1.32 ± 0.94% vs. 6.36 ± 0.56% and 4.80 ± 0.88% respectively; p < 0.001). 13C-exhalation further declined in the presence of advanced fibrosis which was correlated with NASH activity (r = 0.36). The area under the ROC curve (AUROC) for NASH diagnosis was estimated to be 0.87 in the total cohort and 0.83 in patients with no or mild fibrosis (F0-1). Conclusion The 13C-methionine breath test indicates mitochondrial dysfunction in non-alcoholic fatty liver disease and predicts higher stages of disease activity. It may, therefore, be a valuable diagnostic addition for longitudinal monitoring of hepatic (mitochondrial) function in non-alcoholic fatty liver disease. PMID:21810560

  14. The Aspergillus niger D-xylulose kinase gene is co-expressed with genes encoding arabinan degrading enzymes, and is essential for growth on D-xylose and L-arabinose.

    PubMed

    vanKuyk, P A; de Groot, M J; Ruijter, G J; de Vries, R P; Visser, J

    2001-10-01

    The Aspergillus niger D-xylulose kinase encoding gene has been cloned by complementation of a strain deficient in D-xylulose kinase activity. Expression of xkiA was observed in the presence of L-arabinose, L-arabitol and D-xylose. Expression of xkiA is not mediated by XLNR, the xylose-dependent positively-acting xylanolytic regulator. Although the expression of xkiA is subject to carbon catabolite repression, the wide domain regulator CREA is not directly involved. The A. niger D-xylulose kinase was purified to homogeneity, and the molecular mass determined using electrospray ionization mass spectrometry agreed with the calculated molecular mass of 62816.6 Da. The activity of XKIA is highly specific for D-xylulose. Kinetic parameters were determined as Km(D-xylulose) = 0.76 mM and Km(ATP) = 0.061 mM. Increased transcript levels of the genes encoding arabinan and xylan degrading enzymes, observed in the xylulose kinase deficient strain, correlate with increased accumulation of L-arabitol and xylitol, respectively. This result supports the suggestion that L-arabitol may be the specific low molecular mass inducer of the genes involved in arabinan degradation. It also suggests a possible role for xylitol in the induction of xylanolytic genes. Conversely, overproduction of XKIA did not reduce the size of the intracellular arabitol and xylitol pools, and therefore had no effect on expression of genes encoding xylan and arabinan degrading enzymes nor on the activity of the enzymes of the catabolic pathway.

  15. A convenient and reliable method for carbogen breathing in man.

    PubMed

    Kaanders, J H; van der Maazen, R W

    1993-12-01

    The feasibility of carbogen breathing and the intake of nicotinamide in combination with radiation therapy is currently being tested for clinical application. A dependable and convenient system for carbogen breathing is presented which can be easily combined with techniques for immobilization of the patient. The proposed method ensures adequate breathing of carbogen.

  16. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Breathing supply hoses. 197.456 Section 197.456 Shipping....456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply hose is pressure tested prior to being placed into initial service and every 24 months thereafter to...

  17. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Breathing supply hoses. 197.456 Section 197.456 Shipping....456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply hose is pressure tested prior to being placed into initial service and every 24 months thereafter to...

  18. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Breathing supply hoses. 197.456 Section 197.456 Shipping....456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply hose is pressure tested prior to being placed into initial service and every 24 months thereafter to...

  19. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Breathing supply hoses. 197.456 Section 197.456 Shipping....456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply hose is pressure tested prior to being placed into initial service and every 24 months thereafter to...

  20. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Breathing supply hoses. 197.456 Section 197.456 Shipping....456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply hose is pressure tested prior to being placed into initial service and every 24 months thereafter to...

  1. BREATHING PATTERN DISORDERS AND FUNCTIONAL MOVEMENT

    PubMed Central

    Dr. Esformes, Joseph

    2014-01-01

    Study Design: Experimental design Background: Normal breathing mechanics play a key role in posture and spinal stabilization. Breathing Pattern Disorders (BPD) have been shown to contribute to pain and motor control deficits, which can result in dysfunctional movement patterns. The Functional Movement Screen™ (FMS™) has been shown to accurately predict injury in individuals who demonstrate poor movement patterns. The role BPD play on functional movement is not well established. Furthermore, there is currently no single test to clinically diagnose BPD. A variety of methods are used, but correlations between them are poor. Purpose: To examine the relationship between BPD and functional movement and identify correlations between different measures of BPD. Methods: Breathing was assessed in 34 healthy individuals using a multi‐dimensional approach that included biomechanical, biochemical, breathing related symptoms, and breathing functionality measures. Movement was assessed using the FMS™. Analysis, involving independent t‐tests and Pearson correlation were performed to identify associations between measures. Results: Individuals who exhibited biochemical and biomechanical signs of BPD were significantly more likely to score poorly on the FMS™. These studied measures of BPD correlated highly with each other. Conclusion: These results demonstrate the importance of diaphragmatic breathing on functional movement. Inefficient breathing could result in muscular imbalance, motor control alterations, and physiological adaptations that are capable of modifying movement. These findings provide evidence for improved breathing evaluations by clinicians. Level of Evidence: 2B PMID:24567853

  2. Stool microbiome reveals diverse bacterial ureases as confounders of oral urea breath testing for Helicobacter pylori and Mycobacterium tuberculosis in Bamako, Mali.

    PubMed

    Maiga, Mamoudou; Cohen, Keira; Baya, Bocar; Srikrishna, Geetha; Siddiqui, Sophia; Sanogo, Moumine; Somboro, Anou M; Diarra, Bassirou; Diallo, Mariam H; Mazumdar, Varun; Yoder, Christian; Orsega, Susan; Belson, Michael; Kassambara, Hamadoun; Goita, Drissa; Murphy, Robert L; Dao, Sounkalo; Polis, Michael; Diallo, Souleymane; Timmins, Graham S; Dodd, Lori; Earl, Ashlee M; Bishai, William R

    2016-01-01

    Detection of bacterial urease activity has been utilized successfully to diagnose Helicobacter pylori (H. pylori). While Mycobacterium tuberculosis (M. tuberculosis) also possesses an active urease, it is unknown whether detection of mycobacterial urease activity by oral urease breath test (UBT) can be exploited as a rapid point of care biomarker for tuberculosis (TB) in humans. We enrolled 34 individuals newly diagnosed with pulmonary TB and 46 healthy subjects in Bamako, Mali and performed oral UBT, mycobacterial sputum culture and H. pylori testing. Oral UBT had a sensitivity and specificity (95% CI) of 70% (46-88%) and 11% (3-26%), respectively, to diagnose culture-confirmed M. tuberculosis disease among patients without H. pylori, and 100% sensitivity (69-100%) and 11% specificity (3-26%) to diagnose H. pylori among patients without pulmonary TB. Stool microbiome analysis of controls without TB or H. pylori but with positive oral UBT detected high levels of non-H. pylori urease producing organisms, which likely explains the low specificity of oral UBT in this setting and in other reports of oral UBT studies in Africa. PMID:27532494

  3. Prevalence and risk factors of helicobacter pylori in Turkey: a nationally-representative, cross-sectional, screening with the 13C-Urea breath test

    PubMed Central

    2013-01-01

    Background Helicobacter pylori is an important global pathogen infecting approximately 50% of the world’s population. This study was undertaken in order to estimate the prevalence rate of Helicobacter pylori infections among adults living in Turkey and to investigate the associated risk factors. Method This study was a nationally representative cross sectional survey, using weighted multistage stratified cluster sampling. All individuals aged ≥18 years in the selected households were invited to participate in the survey. Ninety two percent (n = 2382) of the households in 55 cities participated; 4622 individuals from these households were tested with the 13C-Urea breath test. Helicobacter pylori prevalence and associated factors were analysed by the t test, chi square and multiple logistic regression with SPSS11.0. Results The weighted overall prevalence was 82.5% (95% CI: 81.0-84.2) and was higher in men. It was lowest in the South which has the major fruit growing areas of the country. The factors included in the final model were sex, age, education, marital status, type of insurance (social security), residential region, alcohol use, smoking, drinking water source. While education was the only significant factor for women, residential region, housing tenure, smoking and alcohol use were significant for men in models by sex. Conclusion In Turkey, Helicobacter pylori prevalence was found to be very high. Individuals who were women, elderly adults, single, had a high educational level, were living in the fruit growing region, had social security from Emekli Sandigi, were drinking bottled water, non smokers and regular alcohol consumers, were under less risk of Helicobacter pylori infection than others. PMID:24359515

  4. Simulated breath waveform control

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    Subsystem was developed which provides twelve waveform controls to breath drive mechanism. Twelve position, magnetically actuated rotary switch is connected to one end of crankshaft drive, such that it makes one complete revolution for each simulated breath. Connections with common wired point are included in modifications made to standard motor speed controller.

  5. From breathing to respiration.

    PubMed

    Fitting, Jean-William

    2015-01-01

    The purpose of breathing remained an enigma for a long time. The Hippocratic school described breathing patterns but did not associate breathing with the lungs. Empedocles and Plato postulated that breathing was linked to the passage of air through pores of the skin. This was refuted by Aristotle who believed that the role of breathing was to cool the heart. In Alexandria, breakthroughs were accomplished in the anatomy and physiology of the respiratory system. Later, Galen proposed an accurate description of the respiratory muscles and the mechanics of breathing. However, his heart-lung model was hampered by the traditional view of two non-communicating vascular systems - veins and arteries. After a period of stagnation in the Middle Ages, knowledge progressed with the discovery of pulmonary circulation. The comprehension of the purpose of breathing progressed by steps thanks to Boyle and Mayow among others, and culminated with the contribution of Priestley and the discovery of oxygen by Lavoisier. Only then was breathing recognized as fulfilling the purpose of respiration, or gas exchange. A century later, a controversy emerged concerning the active or passive transfer of oxygen from alveoli to the blood. August and Marie Krogh settled the dispute, showing that passive diffusion was sufficient to meet the oxygen needs.

  6. From breathing to respiration.

    PubMed

    Fitting, Jean-William

    2015-01-01

    The purpose of breathing remained an enigma for a long time. The Hippocratic school described breathing patterns but did not associate breathing with the lungs. Empedocles and Plato postulated that breathing was linked to the passage of air through pores of the skin. This was refuted by Aristotle who believed that the role of breathing was to cool the heart. In Alexandria, breakthroughs were accomplished in the anatomy and physiology of the respiratory system. Later, Galen proposed an accurate description of the respiratory muscles and the mechanics of breathing. However, his heart-lung model was hampered by the traditional view of two non-communicating vascular systems - veins and arteries. After a period of stagnation in the Middle Ages, knowledge progressed with the discovery of pulmonary circulation. The comprehension of the purpose of breathing progressed by steps thanks to Boyle and Mayow among others, and culminated with the contribution of Priestley and the discovery of oxygen by Lavoisier. Only then was breathing recognized as fulfilling the purpose of respiration, or gas exchange. A century later, a controversy emerged concerning the active or passive transfer of oxygen from alveoli to the blood. August and Marie Krogh settled the dispute, showing that passive diffusion was sufficient to meet the oxygen needs. PMID:25532022

  7. Decreased chewing activity during mouth breathing.

    PubMed

    Hsu, H-Y; Yamaguchi, K

    2012-08-01

    This study examined the effect of mouth breathing on the strength and duration of vertical effect on the posterior teeth using related functional parameters during 3 min of gum chewing in 39 nasal breathers. A CO(2) sensor was placed over the mouth to detect expiratory airflow. When no airflow was detected from the mouth throughout the recording period, the subject was considered a nasal breather and enrolled in the study. Electromyographic (EMG) activity was recorded during 3 min of gum chewing. The protocol was repeated with the nostrils occluded. The strength of the vertical effect was obtained as integrated masseter muscle EMG activity, and the duration of vertical effect was also obtained as chewing stroke count, chewing cycle variation and EMG activity duration above baseline. Baseline activity was obtained from the isotonic EMG activity during jaw movement at 1.6 Hz without making tooth contact. The duration represented the percentage of the active period above baseline relative to the 3-min chewing period. Paired t-test and repeated analysis of variance were used to compare variables between nasal and mouth breathing. The integrated EMG activity and the duration of EMG activity above baseline, chewing stroke count and chewing cycle significantly decreased during mouth breathing compared with nasal breathing (P<0.05). Chewing cycle variance during mouth breathing was significantly greater than nasal breathing (P<0.05). Mouth breathing reduces the vertical effect on the posterior teeth, which can affect the vertical position of posterior teeth negatively, leading to malocclusion.

  8. Upper limb kinematic differences between breathing and non-breathing conditions in front crawl sprint swimming.

    PubMed

    McCabe, Carla B; Sanders, Ross H; Psycharakis, Stelios G

    2015-11-26

    The purpose of this study was to determine whether the breathing action in front crawl (FC) sprint swimming affects the ipsilateral upper limb kinematics relative to a non-breathing stroke cycle (SC). Ten male competitive swimmers performed two 25m FC sprints: one breathing to their preferred side (Br) and one not breathing (NBr). Both swim trials were performed through a 6.75m(3) calibrated space and recorded by six gen-locked JVC KY32 CCD cameras. A paired t-test was used to assess statistical differences between the trials, with a confidence level of p<0.05 accepted as significant. Swimmers were slower (3%) when breathing. Within the entry phase, swimmers had a slower COM horizontal velocity (3.3%), less shoulder flexion (8%), abduction (33%) and roll (4%) when breathing. The pull phase was longer in duration (14%) swimmers had a shallower hand path (11%), less shoulder abduction (11%), a slower hand vertical acceleration (30%) and slower centre of mass (COM) horizontal velocity (3%) when breathing. In the push phase, swimmers had a smaller elbow range of motion (ROM) (38%), faster backwards hand speed (25%) and faster hand vertical acceleration (33%) when breathing. Swimmers rolled their shoulders more (12%) in the recovery phase when breathing. This study confirms that swim performance is compromised by the inclusion of taking a breath in sprint FC swimming. It was proposed that swimmers aim to orient their ipsilateral shoulder into a stronger position by stretching and rolling the shoulders more in the entry phase whilst preparing to take a breath. Swimmers should focus on lengthening the push phase by extending the elbow more and not accelerating the hand too quickly upwards when preparing to inhale. PMID:26456423

  9. Upper limb kinematic differences between breathing and non-breathing conditions in front crawl sprint swimming.

    PubMed

    McCabe, Carla B; Sanders, Ross H; Psycharakis, Stelios G

    2015-11-26

    The purpose of this study was to determine whether the breathing action in front crawl (FC) sprint swimming affects the ipsilateral upper limb kinematics relative to a non-breathing stroke cycle (SC). Ten male competitive swimmers performed two 25m FC sprints: one breathing to their preferred side (Br) and one not breathing (NBr). Both swim trials were performed through a 6.75m(3) calibrated space and recorded by six gen-locked JVC KY32 CCD cameras. A paired t-test was used to assess statistical differences between the trials, with a confidence level of p<0.05 accepted as significant. Swimmers were slower (3%) when breathing. Within the entry phase, swimmers had a slower COM horizontal velocity (3.3%), less shoulder flexion (8%), abduction (33%) and roll (4%) when breathing. The pull phase was longer in duration (14%) swimmers had a shallower hand path (11%), less shoulder abduction (11%), a slower hand vertical acceleration (30%) and slower centre of mass (COM) horizontal velocity (3%) when breathing. In the push phase, swimmers had a smaller elbow range of motion (ROM) (38%), faster backwards hand speed (25%) and faster hand vertical acceleration (33%) when breathing. Swimmers rolled their shoulders more (12%) in the recovery phase when breathing. This study confirms that swim performance is compromised by the inclusion of taking a breath in sprint FC swimming. It was proposed that swimmers aim to orient their ipsilateral shoulder into a stronger position by stretching and rolling the shoulders more in the entry phase whilst preparing to take a breath. Swimmers should focus on lengthening the push phase by extending the elbow more and not accelerating the hand too quickly upwards when preparing to inhale.

  10. Changes in cytochrome P4501A activity during development in common tern chicks fed polychlorinated biphenyls, as measured by the caffeine breath test

    SciTech Connect

    Feyk, L.A.; Giesy, J.P.; Bosveld, A.T.C.; Van den Berg, M.

    2000-03-01

    Cytochrome P4501A (CYPIA) activity is often used as a biomarker of exposure of wildlife to polyhalogenated diaromatic hydrocarbons and is usually measured ex vivo in liver tissue. A caffeine breath test (CBT) with radiolabeled substrate ({sup 14}C-caffeine) was used to measure in vivo CYP1A activity twice during development in 14 common tern (Sterna hirundo) chicks treated with polyhalogenated diaromatic hydrocarbons. Tern hatchlings were fed fish spiked with 3,3{prime}, 4,4{prime},5-pentachlorobiphenyl (PCB 126) and 2,2{prime},4,4{prime},5,5{prime}-hexachlorobiphenyl (PCB 153) such that the diet contained an average of 23, 99, or 561 pg of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents per gram of fish for 21 d. Sixteen additional common tern chicks were similarly dosed with polyhalogenated diaromatic hydrocarbons but were not subjected to the CBT procedure. In weeks 1 and 2, caffeine N-demethylation and ethoxyresorufin-O-deethylation activity on day 21 were elevated in birds that received the greatest PCB dose. There was less constitutive and greater induction of ethoxyresorufin-O-deethylation activity than caffeine N-demethylation. The {sup 14}C-CBT was less invasive than the ethoxyresorufin-O-deethylase assay. Only one morphological parameter differed significantly between CBT subjects and no-CBT subjects fed the same level of PCBs. Bursa weight was significantly less in control CBT subjects than in control no-CBT subjects, but bursa weights did not differ among CBT and no-CBT birds from the two PCB treatment groups. No alterations of survival or growth occurred in CBT subjects compared with no-CBT subjects.

  11. An introduction to the psychophysiology of breathing.

    PubMed

    Ley, R

    1994-06-01

    Breathing can be viewed as an independent variable which affects emotion, cognition, and behavior as well as a dependent variable which reflects changes in emotion, cognition, and behavior. This bidirectional interaction is basic to an appreciation of the significance of breathing in terms of its relevance in research and application. The underlying premise of the present article is that since breathing is a behavior that is under voluntary as well as reflexive control, it can be modified according to the principles of both instrumental training (operant conditioning) and Pavlovian (classical) conditioning. The implications of this premise are relevant to theory, diagnosis, and treatment of stress and anxiety-related disorders (e.g., panic disorder, phobias, test anxiety, occupational strain, and related psychosomatic disorders), and to basic and applied research in the psychophysiology of breathing.

  12. Shortness-of-Breath

    MedlinePlus

    ... can lead to shortness of breath include anxiety, panic attacks, anemia and even constipation. The experience of shortness ... are used to treat patients with anxiety or panic attacks. Other commonly used drugs include bronchodilators to widen ...

  13. Stop, Breathe & Think app.

    PubMed

    Shaw, Natalie

    2014-07-15

    The Stop, Breathe & Think app is free, thanks to underwriting from Tools for Peace, the non-profit organisation that teaches people of all ages how to develop and apply kindness and compassion in their daily lives.

  14. Shortness of Breath

    MedlinePlus

    ... deep breath, which usually results in retention of carbon dioxide and not enough oxygen in blood (obesity hypoventilation ... for anemia), and oximetry or blood oxygen or carbon dioxide levels. Your doctor also may obtain a chest ...

  15. Measurement for breath concentration of hydrogen and methane in horses.

    PubMed

    Sasaki, N; Hobo, S; Yoshihara, T

    1999-09-01

    This study concerns the establishment of a simple testing method for breath concentration of hydrogen and methane in horses. Twenty-eight healthy thoroughbreds and 24 Arabians were used. Breath samples were collected using one-minute closed circulatory respiration through an aluminum bag filled with 10 liters of pure oxygen, which was mounted on the subjects by means of a face mask. Breath samples obtained, were analyzed by gas chromatography. A significant correlation in both hydrogen and methane levels was observed for samples collected at separate times. These findings confirmed the usefulness of our approach for testing breath concentrations of hydrogen and methane in horses.

  16. Breath test for differential diagnosis between small intestinal bacterial overgrowth and irritable bowel disease: An observation on non-absorbable antibiotics

    PubMed Central

    Esposito, I; de Leone, A; Gregorio, G Di; Giaquinto, S; de Magistris, L; Ferrieri, A; Riegler, G

    2007-01-01

    AIM: To estimate the prevalence of small intestine bacterial overgrowth (SIBO) among patients with an earlier diagnosis of irritable bowel disease (IBS) in our geographical area, and to collect information on the use of locally acting non-absorbable antibiotics in the management of SIBO. METHODS: A non-interventional study was conducted in 73 consecutive patients with a symptom-based diagnosis. RESULTS: When the patients underwent a “breath test”, 33 (45.2%) showed the presence of a SIBO. After treatment with rifaximin 1200 mg/d for seven days in 32 patients, 19 (59.4%) showed a negative “breath test” one week later as well as a significant reduction of symptoms, thus confirming the relationship between SIBO and many of the symptoms claimed by patients. In the other 13 patients, “breath test” remained positive, and a further cycle of treatment with ciprofloxacin 500 mg/d was given for 7 additional days, resulting in a negative “breath test” in one patient only. CONCLUSION: (1) about half of the patients with a symptomatic diagnosis of IBS have actually SIBO, which is responsible for most of the symptoms attributed to IBS; (2) only a “breath test” with lactulose (or with glucose in subjects with an intolerance to lactose) can provide a differential diagnosis between IBS and SIBO, with almost identical symptoms; and (3) the use of non-absorbable antibiotics may be useful to reduce the degree of SIBO and related symptoms; it must be accompanied, however, by the correction of the wrong alimentary habits underlying SIBO. PMID:18023092

  17. Investigation of Metabolism of Exogenous Glucose at the Early Stage and Onset of Diabetes Mellitus in Otsuka Long-Evans Tokushima Fatty Rats Using [1, 2, 3-13C]Glucose Breath Tests

    PubMed Central

    Kijima, Sho; Tanaka, Hideki

    2016-01-01

    This study aimed to evaluate changes in glucose metabolism at the early stage and onset of diabetes in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Specifically, after the oral administration of [1, 2, 3-13C]glucose, the levels of exhaled 13CO2, which most likely originated from pyruvate decarboxylation and tricarboxylic acid, were measured. Eight OLETF rats and eight control rats (Long-Evans Tokushima Otsuka [LETO]) were administered 13C-glucose. Three types of 13C-glucose breath tests were performed thrice in each period at 2-week intervals. [3-13C]glucose results in a 13C isotope at position 1 in the pyruvate molecule, which provides 13CO2. The 13C at carbons 1 and 2 of glucose is converted to 13C at carbons 2 and 1 of acetate, respectively, which produce 13CO2. Based on metabolic differences of the labeled sites, glucose metabolism was evaluated using the results of three breath tests. The increase in 13CO2 excretion in OLETF rats was delayed in all three breath tests compared to that in control rats, suggesting that OLETF rats had a lower glucose metabolism than control rats. In addition, overall glucose metabolism increased with age in both groups. The utilization of [2-13C]glucose was suppressed in OLETF rats at 6–12 weeks of age, but they showed higher [3-13C]glucose oxidation than control rats at 22–25 weeks of age. In the [1-13C]glucose breath test, no significant differences in the area under the curve until 180 minutes (AUC180) were observed between OLETF and LETO rats of any age. Glucose metabolism kinetics were different between the age groups and two groups of rats; however, these differences were not significant based on the overall AUC180 of [1-13C]glucose. We conclude that breath 13CO2 excretion is reduced in OLETF rats at the primary stage of prediabetes, indicating differences in glucose oxidation kinetics between OLETF and LETO rats. PMID:27483133

  18. Automatic Recognition of Breathing Route During Sleep Using Snoring Sounds

    NASA Astrophysics Data System (ADS)

    Mikami, Tsuyoshi; Kojima, Yohichiro

    This letter classifies snoring sounds into three breathing routes (oral, nasal, and oronasal) with discriminant analysis of the power spectra and k-nearest neighbor method. It is necessary to recognize breathing route during snoring, because oral snoring is a typical symptom of sleep apnea but we cannot know our own breathing and snoring condition during sleep. As a result, about 98.8% classification rate is obtained by using leave-one-out test for performance evaluation.

  19. A chlorate candle/lithium hydroxide personal breathing apparatus

    NASA Technical Reports Server (NTRS)

    Martin, F. E.

    1972-01-01

    A portable coal mine rescue and survival equipment is reported that consists of a chlorate candle with a lithium hydroxide carbon-dioxide absorbent for oxygen generation, a breathing bag and tubing to conduct breathing to and from the man. A plastic hood incorporating a mouth piece for communication provides also eye protection and prevents inhalation through the nose. Manned testing of a prototype system demonstrated the feasibility of this closed circuit no-maintenance breathing apparatus that provides for good voice communication.

  20. Psychophysiological effects of breathing instructions for stress management.

    PubMed

    Conrad, Ansgar; Müller, Anett; Doberenz, Sigrun; Kim, Sunyoung; Meuret, Alicia E; Wollburg, Eileen; Roth, Walton T

    2007-06-01

    Stressed and tense individuals often are recommended to change the way they breathe. However, psychophysiological effects of breathing instructions on respiration are rarely measured. We tested the immediate effects of short and simple breathing instructions in 13 people seeking treatment for panic disorder, 15 people complaining of daily tension, and 15 controls. Participants underwent a 3-hour laboratory session during which instructions to direct attention to breathing and anti-hyperventilation instructions to breathe more slowly, shallowly, or both were given. Respiratory, cardiac, and electrodermal measures were recorded. The anti-hyperventilation instructions failed to raise end-tidal pCO(2) above initial baseline levels for any of the groups because changes in respiratory rate were compensated for by changes in tidal volume and vice versa. Paying attention to breathing significantly reduced respiratory rate and decreased tidal volume instability compared to the other instructions. Shallow breathing made all groups more anxious than did other instructions. Heart rate and skin conductance were not differentially affected by instructions. We conclude that simple and short instructions to alter breathing do not change respiratory or autonomic measures in the direction of relaxation, except for attention to breathing, which increases respiratory stability. To understand the results of breathing instructions for stress and anxiety management, respiration needs to be monitored physiologically.

  1. Breathing: Rhythmicity, Plasticity, Chemosensitivity

    PubMed Central

    Feldman, Jack L.; Mitchell, Gordon S.; Nattie, Eugene E.

    2010-01-01

    Breathing is a vital behavior that is particularly amenable to experimental investigation. We review recent progress on three problems of broad interest. (i) Where and how is respiratory rhythm generated? The preBötzinger Complex is a critical site, whereas pacemaker neurons may not be essential. The possibility that coupled oscillators are involved is considered. (ii) What are the mechanisms that underlie the plasticity necessary for adaptive changes in breathing? Serotonin-dependent long-term facilitation following intermittent hypoxia is an important example of such plasticity, and a model that can account for this adaptive behavior is discussed. (iii) Where and how are the regulated variables CO2 and pH sensed? These sensors are essential if breathing is to be appropriate for metabolism. Neurons with appropriate chemosensitivity are spread throughout the brainstem; their individual properties and collective role are just beginning to be understood. PMID:12598679

  2. Application of carbon nanotubes to human breath dynamics characterization

    NASA Astrophysics Data System (ADS)

    Hou, Zhongyu; Cai, Bingchu; Xu, Dong

    2006-07-01

    The carbon nanotube composite material and its fabrication techniques are introduced to construct a chip-based electrode system for human breath dynamics characterization. The application of 10V dc bias can generate electric field high enough to effectively collect the charged particles in the human breath. Without using breath collecting tubes, the field tests in the open air exhibit that the system is technologically promising for long-time and noncontact human breath dynamics monitoring, due to its high stability, sensitivity, and safety operation performance with power consumption in the order of 10-5W.

  3. Measurement of nitric oxide in human exhaled breath

    SciTech Connect

    Gordon, S.M.; Spicer, C.W.; Ollison, W.M.

    1997-12-31

    This project was initiated to confirm the reliability of nitric oxide (NO) measurement in the breath matrix, using two different analytical techniques - ozone and luminol chemiluminescence - and to corroborate literature reports of elevated breath NO values. To measure peak oral and nasal NO levels, subjects performed slow vital capacity and breath holding maneuvers directly into the monitors through the mouth and the nose, respectively. Additional measurements were made using normal breathing techniques. Initial interferent tests indicate that measured NO signals are real and are not confounded by measurement artifacts. Similar results were obtained using the two independent analytical methods in dry or humid air. The NO signal was unaffected by maximum concentrations of potential breath interferents, such as sulfur compounds and alkenes. The measured breath NO concentrations were greater than typical room air levels and differed significantly with the breathing technique used. During these tests room air averaged 4-5 ppb NO. Peak oral NO levels were 4.3 {+-} 1.5 ppb during a slow vital capacity maneuver and 8.0 {+-} 5.0 ppb during a breath holding maneuver. By contrast, higher peak nasal NO levels were measured for both slow vital capacity (17.8 {+-} 7.8 ppb) and breath holding maneuvers (45.4 {+-} 29.5 ppb).

  4. Influence of Continuous Table Motion on Patient Breathing Patterns

    SciTech Connect

    Wilbert, Juergen; Baier, Kurt; Richter, Anne; Herrmann, Christian; Ma Lei; Flentje, Michael; Guckenberger, Matthias

    2010-06-01

    Purpose: To investigate the influence of continuous table motion on patient breathing patterns for compensation of moving targets by a robotic treatment couch. Methods and Materials: Fifteen volunteers were placed on a robotic treatment couch, and the couch was moved on different breathing-correlated and -uncorrelated trajectories. External abdominal breathing motion of the patients was measured using an infrared camera system. The influence of table motion on breathing range and pattern was analyzed. Results: Continuous table motion was tolerated well by all test persons. Volunteers reacted differently to table motion. Four test persons showed no change of breathing range and pattern. Increased irregular breathing was observed in 4 patients; however, irregularity was not correlated with table motion. Only 4 test persons showed an increase in mean breathing amplitude of more than 2mm during motion of the couch. The mean cycle period decreased by more than 1 s for 2 test persons only. No abrupt changes in amplitude or cycle period could be observed. Conclusions: The observed small changes in breathing patterns support the application of motion compensation by a robotic treatment couch.

  5. The fast exercise drive to breathe.

    PubMed

    Duffin, James

    2014-02-01

    This paper presents a personal view of research into the exercise drive to breathe that can be observed to act immediately to increase breathing at the start of rhythmic exercise. It is based on a talk given at the Experimental Biology 2013 meeting in a session entitled 'Recent advances in understanding mechanisms regulating breathing during exercise'. This drive to breathe has its origin in a combination of central command, whereby voluntary motor commands to the exercising muscles produce a concurrent respiratory drive, and afferent feedback, whereby afferent information from the exercising muscles affects breathing. The drive at the start and end of rhythmic exercise is proportional to limb movement frequency, and its magnitude decays as exercise continues so that the immediate decrease of ventilation at the end of exercise is about 60% of the immediate increase at the start. With such evidence for the effect of this fast drive to breathe at the start and end of rhythmic exercise, its existence during exercise is hypothesised. Experiments to test this hypothesis have, however, provided debatable evidence. A fast drive to breathe during both ramp and sine wave changes in treadmill exercise speed and grade appears to be present in some individuals, but is not as evident in the general population. Recent sine-wave cycling experiments show that when cadence is varied sinusoidally the ventilation response lags by about 10 s, whereas when pedal loading is varied ventilation lags by about 30 s. It therefore appears that limb movement frequency is effective in influencing ventilation during exercise as well as at the start and end of exercise. PMID:23940383

  6. The fast exercise drive to breathe.

    PubMed

    Duffin, James

    2014-02-01

    This paper presents a personal view of research into the exercise drive to breathe that can be observed to act immediately to increase breathing at the start of rhythmic exercise. It is based on a talk given at the Experimental Biology 2013 meeting in a session entitled 'Recent advances in understanding mechanisms regulating breathing during exercise'. This drive to breathe has its origin in a combination of central command, whereby voluntary motor commands to the exercising muscles produce a concurrent respiratory drive, and afferent feedback, whereby afferent information from the exercising muscles affects breathing. The drive at the start and end of rhythmic exercise is proportional to limb movement frequency, and its magnitude decays as exercise continues so that the immediate decrease of ventilation at the end of exercise is about 60% of the immediate increase at the start. With such evidence for the effect of this fast drive to breathe at the start and end of rhythmic exercise, its existence during exercise is hypothesised. Experiments to test this hypothesis have, however, provided debatable evidence. A fast drive to breathe during both ramp and sine wave changes in treadmill exercise speed and grade appears to be present in some individuals, but is not as evident in the general population. Recent sine-wave cycling experiments show that when cadence is varied sinusoidally the ventilation response lags by about 10 s, whereas when pedal loading is varied ventilation lags by about 30 s. It therefore appears that limb movement frequency is effective in influencing ventilation during exercise as well as at the start and end of exercise.

  7. The fast exercise drive to breathe

    PubMed Central

    Duffin, James

    2014-01-01

    This paper presents a personal view of research into the exercise drive to breathe that can be observed to act immediately to increase breathing at the start of rhythmic exercise. It is based on a talk given at the Experimental Biology 2013 meeting in a session entitled ‘Recent advances in understanding mechanisms regulating breathing during exercise’. This drive to breathe has its origin in a combination of central command, whereby voluntary motor commands to the exercising muscles produce a concurrent respiratory drive, and afferent feedback, whereby afferent information from the exercising muscles affects breathing. The drive at the start and end of rhythmic exercise is proportional to limb movement frequency, and its magnitude decays as exercise continues so that the immediate decrease of ventilation at the end of exercise is about 60% of the immediate increase at the start. With such evidence for the effect of this fast drive to breathe at the start and end of rhythmic exercise, its existence during exercise is hypothesised. Experiments to test this hypothesis have, however, provided debatable evidence. A fast drive to breathe during both ramp and sine wave changes in treadmill exercise speed and grade appears to be present in some individuals, but is not as evident in the general population. Recent sine-wave cycling experiments show that when cadence is varied sinusoidally the ventilation response lags by about 10 s, whereas when pedal loading is varied ventilation lags by about 30 s. It therefore appears that limb movement frequency is effective in influencing ventilation during exercise as well as at the start and end of exercise. PMID:23940383

  8. Life and Breath

    ERIC Educational Resources Information Center

    Ellis, Helen D.

    1974-01-01

    This article describes a public education program combining the screening process and a follow-up program for teaching victims of emphysema and other respiratory diseases how to better their living condition through proper breathing, avoidance of air pollutants and cigarette smoking, and taking better care of themselves physically. (PD)

  9. Metabolic breath analyzer

    NASA Technical Reports Server (NTRS)

    Perry, C. L.

    1971-01-01

    Instrument measures metabolic breathing rate and dynamics of human beings in atmospheres ranging from normal air to 100 percent oxygen at ambient pressures from 14.7 to 3.0 psia. Measurements are made at rest or performing tasks up to maximum physical capacity under either zero or normal gravity.

  10. Breathing Like a Fish

    ERIC Educational Resources Information Center

    Katsioloudis, Petros J.

    2010-01-01

    Being able to dive and breathe underwater has been a challenge for thousands of years. In 1980, Fuji Systems of Tokyo developed a series of prototype gills for divers as a way of demonstrating just how good its membranes are. Even though gill technology has not yet reached the point where recipients can efficiently use implants to dive underwater,…

  11. 49 CFR 40.265 - What happens when an employee is unable to provide a sufficient amount of breath for an alcohol...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... a sufficient amount of breath for an alcohol test? 40.265 Section 40.265 Transportation Office of... sufficient amount of breath for an alcohol test? (a) If an employee does not provide a sufficient amount of breath to permit a valid breath test, you must take the steps listed in this section. (b) As the BAT...

  12. 49 CFR 40.265 - What happens when an employee is unable to provide a sufficient amount of breath for an alcohol...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... a sufficient amount of breath for an alcohol test? 40.265 Section 40.265 Transportation Office of... sufficient amount of breath for an alcohol test? (a) If an employee does not provide a sufficient amount of breath to permit a valid breath test, you must take the steps listed in this section. (b) As the BAT...

  13. 49 CFR 40.265 - What happens when an employee is unable to provide a sufficient amount of breath for an alcohol...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... a sufficient amount of breath for an alcohol test? 40.265 Section 40.265 Transportation Office of... sufficient amount of breath for an alcohol test? (a) If an employee does not provide a sufficient amount of breath to permit a valid breath test, you must take the steps listed in this section. (b) As the BAT...

  14. 49 CFR 40.265 - What happens when an employee is unable to provide a sufficient amount of breath for an alcohol...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... a sufficient amount of breath for an alcohol test? 40.265 Section 40.265 Transportation Office of... sufficient amount of breath for an alcohol test? (a) If an employee does not provide a sufficient amount of breath to permit a valid breath test, you must take the steps listed in this section. (b) As the BAT...

  15. 49 CFR 40.265 - What happens when an employee is unable to provide a sufficient amount of breath for an alcohol...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... a sufficient amount of breath for an alcohol test? 40.265 Section 40.265 Transportation Office of... sufficient amount of breath for an alcohol test? (a) If an employee does not provide a sufficient amount of breath to permit a valid breath test, you must take the steps listed in this section. (b) As the BAT...

  16. Breath Analysis in Disease Diagnosis: Methodological Considerations and Applications

    PubMed Central

    Lourenço, Célia; Turner, Claire

    2014-01-01

    Breath analysis is a promising field with great potential for non-invasive diagnosis of a number of disease states. Analysis of the concentrations of volatile organic compounds (VOCs) in breath with an acceptable accuracy are assessed by means of using analytical techniques with high sensitivity, accuracy, precision, low response time, and low detection limit, which are desirable characteristics for the detection of VOCs in human breath. “Breath fingerprinting”, indicative of a specific clinical status, relies on the use of multivariate statistics methods with powerful in-built algorithms. The need for standardisation of sample collection and analysis is the main issue concerning breath analysis, blocking the introduction of breath tests into clinical practice. This review describes recent scientific developments in basic research and clinical applications, namely issues concerning sampling and biochemistry, highlighting the diagnostic potential of breath analysis for disease diagnosis. Several considerations that need to be taken into account in breath analysis are documented here, including the growing need for metabolomics to deal with breath profiles. PMID:24957037

  17. Particle concentration in exhaled breath

    SciTech Connect

    Fairchild, C.I.; Stampfer, J.F.

    1987-11-01

    Measurements were made of the number of concentration of particles in exhaled breath under various conditions of exercise. A laser light scattering particle spectrometer was used to count particles exhaled by test subjects wearing respirators in a challenge environment of clean, dry air. Precautions were taken to ensure that particles were not generated by the respirators and that no extraneous water or other particles were produced in the humid exhaled air. The number of particles detected in exhales air varied over a range from <0.10 to approx. 4 particles/cm/sup 3/ depending upon the test subject and his activity. Subjects at rest exhaled the lowest concentration of particles, whereas exercises producing a faster respiration rate caused increased exhalation of particles. Exhaled particle concentration can limit the usefulness of nondiscriminating, ambient challenge aerosols for the fit testing of highly protective respirators.

  18. Applied breath analysis: an overview of the challenges and opportunities in developing and testing sensor technology for human health monitoring in aerospace and clinical applications

    PubMed Central

    Hunter, Gary W; Dweik, Raed A

    2010-01-01

    The aerospace industry requires the development of a range of chemical sensor technologies for such applications as leak detection, emission monitoring, fuel leak detection, environmental monitoring, and fire detection. A family of chemical sensors are being developed based on micromachining and microfabrication technology to fabricate microsensors with minimal size, weight, and power consumption, and the use of nanomaterials and structures to develop sensors with improved stability combined with higher sensitivity. However, individual sensors are limited in the amount of information that they can provide in environments that contain multiple chemical species. Thus, sensor arrays are being developed to address detection needs in such multi-species environments. These technologies and technical approaches have direct relevance to breath monitoring for clinical applications. This paper gives an overview of developing cutting-edge sensor technology and possible barriers to new technology implementation. This includes lessons learned from previous microsensor development, recent work in development of a breath monitoring system, and future directions in the implementation of cutting edge sensor technology. Clinical applications and the potential impact to the biomedical field of miniaturized smart gas sensor technology are discussed. PMID:20622933

  19. Crew equipment applications - Firefighter's Breathing System.

    NASA Technical Reports Server (NTRS)

    Smith, W. L.

    1973-01-01

    The Firefighter's Breathing System (FBS) represents a significant step in applying NASA's crew equipment technologists and technologies to civilian sector problems. This paper describes the problem, the utilization of user-design committees as a forum for development of design goals, the design of the FBS, and the field test program to be conducted.

  20. Improving estimation of cardiac vagal tone during spontaneous breathing using a paced breathing calibration.

    PubMed

    Wilhelm, Frank H; Grossman, Paul; Coyle, Michael A

    2004-01-01

    Respiratory sinus arrhythmia (RSA) is a commonly employed non-invasive measure of cardiac vagal control. It has been demonstrated that respiratory parameters such as tidal volume and respiratory frequency can change RSA without altering tonic vagal activity. Thus, within-individual comparisons of cardiac vagal control across different behavioral tasks might benefit from an adjustment for respiratory confounds. We tested an adjustment method using transfer function analysis and paced breathing at 3 different respiratory frequencies as the basis for regressing out respiratory related RSA changes in a task where breathing was not controlled. Electrocardiogram and calibrated respiration were recorded with the LifeShirt system from 15 young adult participants. Time series of RR intervals and lung volume change were computed and the respiration-to-RR-interval transfer-function magnitude (RSA-TF, in ms/liter) estimated. Mean (SD) of RSA-TF was 142 (68) at 9 breaths/min, 78 (52) at 13.5 breaths/min, 57 (43) at 18 breaths/min, and 121 (56) during baseline, with a respiratory frequency of 12.5 (3.8) breaths/min. At baseline, measured and predicted RSA-TF values (mean 94 +/- 82) differed significantly and correlated only moderately (r = 0.67). Factors contributing to a less than perfect correlation included slightly elevated subjective anxiety levels and hyperventilation during paced breathing, both of which may have affected cardiac vagal tone. This study demonstrates a novel procedure for computing a respiratory unrelated RSA index. Results provide some support for the utility of this adjustment method for improving the estimation of cardiac vagal tone from RSA, but also indicate that the paced breathing procedure may need to be further refined.

  1. Tests for H. pylori

    MedlinePlus

    Peptic ulcer disease - H. pylori ; PUD - H. pylori ... There are several methods to test for H. pylori infection. Breath Test (Carbon Isotope-urea Breath Test, or UBT) Up to 2 weeks before the test, you need to stop taking ...

  2. Emergency Response Breathing Apparatus

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Aerospace Design & Development, Inc.'s (ADD's) SCAMP was developed under an SBIR contract through Kennedy Space Center. SCAMP stands for Supercritical Air Mobility Pack. The technology came from the life support fuel cell support systems used for the Apollo and Space Shuttle programs. It uses supercritical cryogenic air and is able to function in microgravity environments. SCAMP's self-contained breathing apparatus(SCBA) systems are also ground-based and can provide twice as much air than traditional SCBA's due to its high-density capacity. The SCAMP system was designed for use in launch pad emergency rescues. ADD also developed a protective suit for use with SCAMP that is smaller and lighter system than the old ones. ADD's SCAMP allows for body cooling and breathing from the supercritical cryogenic air, requiring no extra systems. The improvement over the traditional SCBA allows for a reduction of injuries, such as heat stress, and makes it easier for rescuers to save lives.

  3. [Prevalence of mouth breathing in children from an elementary school].

    PubMed

    Felcar, Josiane Marques; Bueno, Izabele Rafael; Massan, Ana Carolina Silva; Torezan, Roberta Pereira; Cardoso, Jefferson Rosa

    2010-03-01

    The objective of this article is to identify the prevalence of mouth breathing in children from an elementary school. 496 questionnaires were answered by 1st and 4th grade children's parents or sponsors in order to identify mouth-breathing. There were questions about habits, sleeping, behavior, eating, personal care and breathing. Mann-Whitney and the Chi-square tests were used to compare the variables between mouth-breathing and nose-breathing among the groups. To measure the exposure effect of the explanatory variables on mouth breathing, the test of logistic regression was used and its magnitude was calculated through Odds Ratio. The statistical significance was set at 5%, and the rate of returned questionnaires was 84.5%. The prevalence of the mouthbreathing over this population was 56.8%. The average age was 7 years old (6-9). There was no significant statistical difference between genders, considering 49.1% male and 50.9% female. The final model of logistic regression identified the variables dribble, sleeps well (negative association) and snores as factors that predict the occurrence of the mouth-breathing. The prevalence of mouthbreathing was similar to related in the literature. The variables dribble, sleeps well (negative association) and snores may be factors that predict the occurrence of mouth-breathing.

  4. [TMJ, eating and breathing].

    PubMed

    Cheynet, F

    2016-09-01

    The study of the relationship between temporomandibular joints (TMJ), mastication and ventilation and the involvement of these two functions in the genesis of primary Temporomandibular Disorders (TMD) and in some dentofacial deformities, was initiated in France, more than 30years, by Professor Raymond Gola. Once criticized the weakness of the scientific literature in this domain, the originality of the TMJ within the masticatory system is recalled with its huge adaptation potential to very different biomechanical constraints according to the age and masticatory activities during the day. But the biomechanics of the masticatory system does not stop at night and the positions of the mandible and head during sleep should be studied carefully. In case of nocturnal mouth breathing with open mouth, the predominant sleeping position (generating small but long-term strengths) may be deleterious to the condyle-disc complex, to the surrounding muscles and the occlusal relationships. Some condyle-disc displacements and asymmetric malocclusions occur in this long portion of life what sleep, especially as oral breathing leads to a lot of dysfunctions (low position of the tongue, labio-lingual dysfunctions, exacerbation of bruxism sleep…). The aim of this work was to share our multidisciplinary experience of the biomechanical consequences of the nocturnal mouth breathing on the face involving orthodontists, maxillofacial surgeons, ENT, allergists, speech therapists, physiotherapists and radiologists.

  5. [TMJ, eating and breathing].

    PubMed

    Cheynet, F

    2016-09-01

    The study of the relationship between temporomandibular joints (TMJ), mastication and ventilation and the involvement of these two functions in the genesis of primary Temporomandibular Disorders (TMD) and in some dentofacial deformities, was initiated in France, more than 30years, by Professor Raymond Gola. Once criticized the weakness of the scientific literature in this domain, the originality of the TMJ within the masticatory system is recalled with its huge adaptation potential to very different biomechanical constraints according to the age and masticatory activities during the day. But the biomechanics of the masticatory system does not stop at night and the positions of the mandible and head during sleep should be studied carefully. In case of nocturnal mouth breathing with open mouth, the predominant sleeping position (generating small but long-term strengths) may be deleterious to the condyle-disc complex, to the surrounding muscles and the occlusal relationships. Some condyle-disc displacements and asymmetric malocclusions occur in this long portion of life what sleep, especially as oral breathing leads to a lot of dysfunctions (low position of the tongue, labio-lingual dysfunctions, exacerbation of bruxism sleep…). The aim of this work was to share our multidisciplinary experience of the biomechanical consequences of the nocturnal mouth breathing on the face involving orthodontists, maxillofacial surgeons, ENT, allergists, speech therapists, physiotherapists and radiologists. PMID:27554491

  6. A fully integrated standalone portable cavity ringdown breath acetone analyzer

    NASA Astrophysics Data System (ADS)

    Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

    2015-09-01

    Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

  7. A fully integrated standalone portable cavity ringdown breath acetone analyzer.

    PubMed

    Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

    2015-09-01

    Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

  8. Diving bradycardia and breath-holding time in man.

    PubMed

    Sterba, J A; Lundgren, C E

    1985-06-01

    The hypothesis that the diving response, recorded as diving bradycardia during submersed breath holding in man, would enhance his breath-holding time was tested. Five certified scuba divers served as subjects. They performed breath holds of maximal duration while nonimmersed and during submersion in cool (32 degrees C), cold (20 degrees C), and thermoneutral (35 degrees C) water. The mean breath-holding time and heart rate during the nonimmersed (control) condition were, respectively, 111.2 +/- 14.1 (SE) s and 64.1 +/- 4.7 (SE) beats/min, the relatively long breath-holding times being due primarily to the so-called short-term training effect. Compared to the control values the breath-holding time in 20 degrees C water was 54.9% shorter and heart rate 25.9% lower, in 32 degrees C water the breath-holding time was not different and heart rate was 28.1% lower, and in 35 degrees C water the breath-holding time was longer by 25.6% while there was no difference in heart rate. In all conditions the breath-hold breaking point alveolar PCO2 was the same at about 52 mmHg. The shortening of the breath holds in cold water was ascribed to a 256% increase (over nonimmersed control) in metabolic rate as well as a respiratory drive due to stimulation of skin cold receptors. As for the prolongation of breath holds in thermoneutral water, it was hypothesized that immersion caused a delay in the build-up of chemical stimuli at the chemoreceptors.

  9. Association between halitosis and mouth breathing in children

    PubMed Central

    Motta, Lara Jansiski; Bachiega, Joanna Carolina; Guedes, Carolina Cardoso; Laranja, Lorena Tristão; Bussadori, Sandra Kalil

    2011-01-01

    OBJECTIVE: To determine whether there is a correlation between halitosis and mouth breathing in children. STUDY DESIGN: Fifty-five children between 3 and 14 years of age were divided into two groups (nasal and mouth breathing) for the assessment of halitosis. A descriptive analysis was conducted on the degree of halitosis in each group. The chi-square test was used for comparison between groups, with a 5% level of significance. RESULTS: There was a significantly greater number of boys with the mouth-breathing pattern than girls. A total of 23.6% of the participants had no mouth odor, 12.7% had mild odor, 12.7% had moderate odor and 50.9% had strong odor. There was a statistically significant association between halitosis and mouth breathing. CONCLUSIONS: The occurrence of halitosis was high among the children evaluated, and there was a statistically significant association between halitosis and mouth breathing. PMID:21808855

  10. Determination of breath acetone in 149 type 2 diabetic patients using a ringdown breath-acetone analyzer.

    PubMed

    Sun, Meixiu; Chen, Zhuying; Gong, Zhiyong; Zhao, Xiaomeng; Jiang, Chenyu; Yuan, Yuan; Wang, Zhennang; Li, Yingxin; Wang, Chuji

    2015-02-01

    Over 90% of diabetic patients have Type 2 diabetes. Although an elevated mean breath acetone concentration has been found to exist in Type 1 diabetes (T1D), information on breath acetone in Type 2 diabetes (T2D) has yet to be obtained. In this study, we first used gas chromatography-mass spectrometry (GC-MS) to validate a ringdown breath-acetone analyzer based on the cavity-ringdown-spectroscopy technique, through comparing breath acetone concentrations in the range 0.5-2.5 ppm measured using both methods. The linear fitting of R = 0.99 suggests that the acetone concentrations obtained using both methods are consistent with a largest standard deviation of ±0.4 ppm in the lowest concentration of the range. Next, 620 breath samples from 149 T2D patients and 42 healthy subjects were collected and tested using the breath analyzer. Four breath samples were taken from each subject under each of four different conditions: fasting, 2 h post-breakfast, 2 h post-lunch, and 2 h post-dinner. Simultaneous blood glucose levels were also measured using a standard diabetic-management blood-glucose meter. For the 149 T2D subjects, their exhaled breath acetone concentrations ranged from 0.1 to 19.8 ppm; four different ranges of breath acetone concentration, 0.1-19.8, 0.1-7.1, 0.1-6.3, and 0.1-9.5 ppm, were obtained for the subjects under the four different conditions, respectively. For the 42 healthy subjects, their breath acetone concentration ranged from 0.1 to 2.6 ppm; four different ranges of breath acetone concentration, 0.3-2.6, 0.1-2.6, 0.1-1.7, and 0.3-1.6 ppm, were obtained for the four different conditions. The mean breath acetone concentration of the 149 T2D subjects was determined to be 1.5 ± 1.5 ppm, which was 1.5 times that of 1.0 ± 0.6 ppm for the 42 healthy subjects. No correlation was found between the breath acetone concentration and the blood glucose level of the T2D subjects and the healthy volunteers. This study using a relatively large number of

  11. Breath-by-breath measurement of particle deposition in the lung of spontaneously breathing rats.

    PubMed

    Karrasch, S; Eder, G; Bolle, I; Tsuda, A; Schulz, H

    2009-10-01

    A number of deposition models for humans, as well as experimental animals, have been described. However, no breath-by-breath deposition measurement in rats has been reported to date. The objective of this study is to determine lung deposition of micrometer-sized particles as a function of breathing parameters in the adult rat lung. A new aerosol photometry system was designed to measure deposition of nonhygroscopic, 2-mum sebacate particles in anesthetized, intubated, and spontaneously breathing 90-day-old Wistar-Kyoto rats placed in a size-adjusted body plethysmograph box. Instrumental dead space of the system was minimized down to 310 microl (i.e., approximately 20% of respiratory dead space). The system allows continuous monitoring of particle concentration in the respired volume. Breathing parameters, such as respiratory rate (f), tidal volume (Vt), as well as inspiration/expiration times, were also monitored at different levels of anesthesia. The results showed that Vt typically varied between 1.5 and 4.0 ml for regular breathing and between 4.0 and 10.0 ml for single-sigh breaths; f ranged from 40 to 200 breaths/min. Corresponding deposition values varied between 5 and 50%, depending on breath-by-breath breathing patterns. The best fit of deposition (D) was achieved by a bilinear function of Vt and f and found to be D = 11.0 - 0.09.f + 3.75.Vt. We conclude that our approach provides more realistic conditions for the measurement of deposition than conventional models using ventilated animals and allows us to analyze the correlation between breath-specific deposition and spontaneous breathing patterns.

  12. Probing plasmonic breathing modes optically

    SciTech Connect

    Krug, Markus K. Reisecker, Michael; Hohenau, Andreas; Ditlbacher, Harald; Trügler, Andreas; Hohenester, Ulrich; Krenn, Joachim R.

    2014-10-27

    The confinement of surface plasmon modes in flat nanoparticles gives rise to plasmonic breathing modes. With a vanishing net dipole moment, breathing modes do not radiate, i.e., they are optically dark. Having thus escaped optical detection, breathing modes were only recently revealed in silver nanodisks with electron energy loss spectroscopy in an electron microscope. We show that for disk diameters >200 nm, retardation induced by oblique optical illumination relaxes the optically dark character. This makes breathing modes and thus the full plasmonic mode spectrum accessible to optical spectroscopy. The experimental spectroscopy data are in excellent agreement with numerical simulations.

  13. Cannabinoids in Exhaled Breath following Controlled Administration of Smoked Cannabis

    PubMed Central

    Himes, Sarah K.; Scheidweiler, Karl B.; Beck, Olof; Gorelick, David A.; Desrosiers, Nathalie A.; Huestis, Marilyn A.

    2015-01-01

    BACKGROUND Δ9-Tetrahydrocannabinol (THC), 11-nor-9-carboxy-THC (THCCOOH), and cannabinol (CBN) were measured in breath following controlled cannabis smoking to characterize the time course and window of detection of breath cannabinoids. METHODS Exhaled breath was collected from chronic (≥4 times per week) and occasional (breath pads, solid-phase extraction, and liquid chromatography–tandem mass spectrometry quantification. RESULTS THC was the major cannabinoid in breath; no sample contained THCCOOH and only 1 contained CBN. Among chronic smokers (n = 13), all breath samples were positive for THC at 0.89 h, 76.9% at 1.38 h, and 53.8% at 2.38 h, and only 1 sample was positive at 4.2 h after smoking. Among occasional smokers (n = 11), 90.9% of breath samples were THC-positive at 0.95 h and 63.6% at 1.49 h. One occasional smoker had no detectable THC. Analyte recovery from breath pads by methanolic extraction was 84.2%–97.4%. Limits of quantification were 50 pg/pad for THC and CBN and 100 pg/pad for THCCOOH. Solid-phase extraction efficiency was 46.6%–52.1% (THC) and 76.3%–83.8% (THCCOOH, CBN). Matrix effects were −34.6% to 12.3%. Cannabinoids fortified onto breath pads were stable (≤18.2% concentration change) for 8 h at room temperature and −20°C storage for 6 months. CONCLUSIONS Breath may offer an alternative matrix for testing for recent driving under the influence of cannabis, but is limited to a short detection window (0.5–2 h). PMID:24046200

  14. Patient's breath controls comfort devices

    NASA Technical Reports Server (NTRS)

    Schrader, M.; Carpenter, B.; Nichols, C. D.

    1972-01-01

    Patient assist system for totally disabled persons was developed which permits a person, so paralyzed as to be unable to move, to activate by breathing, a call system to summon assistance, turn the page of a book, ajust his bed, or do any one of a number of other things. System consists of patient assist control and breath actuated switch.

  15. BREATHE to Understand©

    ERIC Educational Resources Information Center

    Swisa, Maxine

    2015-01-01

    BREATHE is an acronym for Breathe, Reflect, Empathize, Accept, Thank, Hearten, Engage. The addition of Understand allows for a holistic approach to living a healthy and balanced life both inside and outside the classroom. This paper took form as a result of my personal, spiritual journey, as well as my teaching practice. I noticed that the…

  16. How and When Do Insects Rely on Endogenous Protein and Lipid Resources during Lethal Bouts of Starvation? A New Application for 13C-Breath testing

    PubMed Central

    McCue, Marshall D.; Guzman, R. Marena; Passement, Celeste A.; Davidowitz, Goggy

    2015-01-01

    Most of our understanding about the physiology of fasting and starvation comes from studies of vertebrates; however, for ethical reasons, studies that monitor vertebrates through the lethal endpoint are scant. Insects are convenient models to characterize the comparative strategies used to cope with starvation because they have diverse life histories and have evolved under the omnipresent challenge of food limitation. Moreover, we can study the physiology of starvation through its natural endpoint. In this study we raised populations of five species of insects (adult grasshoppers, crickets, cockroaches, and larval beetles and moths) on diets labeled with either 13C-palmitic acid or 13C-leucine to isotopically enrich the lipids or the proteins in their bodies, respectively. The insects were allowed to become postabsorptive and then starved. We periodically measured the δ13C of the exhaled breath to characterize how each species adjusted their reliance on endogenous lipids and proteins as energy sources. We found that starving insects employ a wide range of strategies for regulating lipid and protein oxidation. All of the insects except for the beetle larvae were capable of sharply reducing reliance on protein oxidation; however, this protein sparing strategy was usually unsustainable during the entire starvation period. All insects increased their reliance on lipid oxidation, but while some species (grasshoppers, cockroaches, and beetle larvae) were still relying extensively on lipids at the time of death, other species (crickets and moth larvae) allowed rates of lipid oxidation to return to prestarvation levels. Although lipids and proteins are critical metabolic fuels for both vertebrates and insects, insects apparently exhibit a much wider range of strategies for rationing these limited resources during starvation. PMID:26465334

  17. How and When Do Insects Rely on Endogenous Protein and Lipid Resources during Lethal Bouts of Starvation? A New Application for 13C-Breath testing.

    PubMed

    McCue, Marshall D; Guzman, R Marena; Passement, Celeste A; Davidowitz, Goggy

    2015-01-01

    Most of our understanding about the physiology of fasting and starvation comes from studies of vertebrates; however, for ethical reasons, studies that monitor vertebrates through the lethal endpoint are scant. Insects are convenient models to characterize the comparative strategies used to cope with starvation because they have diverse life histories and have evolved under the omnipresent challenge of food limitation. Moreover, we can study the physiology of starvation through its natural endpoint. In this study we raised populations of five species of insects (adult grasshoppers, crickets, cockroaches, and larval beetles and moths) on diets labeled with either 13C-palmitic acid or 13C-leucine to isotopically enrich the lipids or the proteins in their bodies, respectively. The insects were allowed to become postabsorptive and then starved. We periodically measured the δ13C of the exhaled breath to characterize how each species adjusted their reliance on endogenous lipids and proteins as energy sources. We found that starving insects employ a wide range of strategies for regulating lipid and protein oxidation. All of the insects except for the beetle larvae were capable of sharply reducing reliance on protein oxidation; however, this protein sparing strategy was usually unsustainable during the entire starvation period. All insects increased their reliance on lipid oxidation, but while some species (grasshoppers, cockroaches, and beetle larvae) were still relying extensively on lipids at the time of death, other species (crickets and moth larvae) allowed rates of lipid oxidation to return to prestarvation levels. Although lipids and proteins are critical metabolic fuels for both vertebrates and insects, insects apparently exhibit a much wider range of strategies for rationing these limited resources during starvation. PMID:26465334

  18. How and When Do Insects Rely on Endogenous Protein and Lipid Resources during Lethal Bouts of Starvation? A New Application for 13C-Breath testing.

    PubMed

    McCue, Marshall D; Guzman, R Marena; Passement, Celeste A; Davidowitz, Goggy

    2015-01-01

    Most of our understanding about the physiology of fasting and starvation comes from studies of vertebrates; however, for ethical reasons, studies that monitor vertebrates through the lethal endpoint are scant. Insects are convenient models to characterize the comparative strategies used to cope with starvation because they have diverse life histories and have evolved under the omnipresent challenge of food limitation. Moreover, we can study the physiology of starvation through its natural endpoint. In this study we raised populations of five species of insects (adult grasshoppers, crickets, cockroaches, and larval beetles and moths) on diets labeled with either 13C-palmitic acid or 13C-leucine to isotopically enrich the lipids or the proteins in their bodies, respectively. The insects were allowed to become postabsorptive and then starved. We periodically measured the δ13C of the exhaled breath to characterize how each species adjusted their reliance on endogenous lipids and proteins as energy sources. We found that starving insects employ a wide range of strategies for regulating lipid and protein oxidation. All of the insects except for the beetle larvae were capable of sharply reducing reliance on protein oxidation; however, this protein sparing strategy was usually unsustainable during the entire starvation period. All insects increased their reliance on lipid oxidation, but while some species (grasshoppers, cockroaches, and beetle larvae) were still relying extensively on lipids at the time of death, other species (crickets and moth larvae) allowed rates of lipid oxidation to return to prestarvation levels. Although lipids and proteins are critical metabolic fuels for both vertebrates and insects, insects apparently exhibit a much wider range of strategies for rationing these limited resources during starvation.

  19. Yoga breathing, meditation, and longevity.

    PubMed

    Brown, Richard P; Gerbarg, Patricia L

    2009-08-01

    Yoga breathing is an important part of health and spiritual practices in Indo-Tibetan traditions. Considered fundamental for the development of physical well-being, meditation, awareness, and enlightenment, it is both a form of meditation in itself and a preparation for deep meditation. Yoga breathing (pranayama) can rapidly bring the mind to the present moment and reduce stress. In this paper, we review data indicating how breath work can affect longevity mechanisms in some ways that overlap with meditation and in other ways that are different from, but that synergistically enhance, the effects of meditation. We also provide clinical evidence for the use of yoga breathing in the treatment of depression, anxiety, post-traumatic stress disorder, and for victims of mass disasters. By inducing stress resilience, breath work enables us to rapidly and compassionately relieve many forms of suffering.

  20. Rapid shallow breathing index

    PubMed Central

    Karthika, Manjush; Al Enezi, Farhan A.; Pillai, Lalitha V.; Arabi, Yaseen M.

    2016-01-01

    Predicting successful liberation of patients from mechanical ventilation has been a focus of interest to clinicians practicing in intensive care. Various weaning indices have been investigated to identify an optimal weaning window. Among them, the rapid shallow breathing index (RSBI) has gained wide use due to its simple technique and avoidance of calculation of complex pulmonary mechanics. Since its first description, several modifications have been suggested, such as the serial measurements and the rate of change of RSBI, to further improve its predictive value. The objective of this paper is to review the utility of RSBI in predicting weaning success. In addition, the use of RSBI in specific patient populations and the reported modifications of RSBI technique that attempt to improve the utility of RSBI are also reviewed. PMID:27512505

  1. Rapid shallow breathing index.

    PubMed

    Karthika, Manjush; Al Enezi, Farhan A; Pillai, Lalitha V; Arabi, Yaseen M

    2016-01-01

    Predicting successful liberation of patients from mechanical ventilation has been a focus of interest to clinicians practicing in intensive care. Various weaning indices have been investigated to identify an optimal weaning window. Among them, the rapid shallow breathing index (RSBI) has gained wide use due to its simple technique and avoidance of calculation of complex pulmonary mechanics. Since its first description, several modifications have been suggested, such as the serial measurements and the rate of change of RSBI, to further improve its predictive value. The objective of this paper is to review the utility of RSBI in predicting weaning success. In addition, the use of RSBI in specific patient populations and the reported modifications of RSBI technique that attempt to improve the utility of RSBI are also reviewed. PMID:27512505

  2. Breathing zone air sampler

    DOEpatents

    Tobin, John

    1989-01-01

    A sampling apparatus is provided which comprises a sampler for sampling air in the breathing zone of a wearer of the apparatus and a support for the sampler preferably in the form of a pair of eyeglasses. The sampler comprises a sampling assembly supported on the frame of the eyeglasses and including a pair of sample transport tubes which are suspended, in use, centrally of the frame so as to be disposed on opposite sides of the nose of the wearer and which each include an inlet therein that, in use, is disposed adjacent to a respective nostril of the nose of the wearer. A filter holder connected to sample transport tubes supports a removable filter for filtering out particulate material in the air sampled by the apparatus. The sample apparatus is connected to a pump for drawing air into the apparatus through the tube inlets so that the air passes through the filter.

  3. Growth of breath figures

    NASA Astrophysics Data System (ADS)

    Beysens, D.; Knobler, C. M.

    1986-09-01

    Measurements are reported of the growth of breath figures, the patterns that form when a vapor is condensed onto a cold surface. Water vapor was condensed on glass slides and the pattern was studied by direct observation and light scattering as a function of the contact angle theta, flux F, degree of supersaturation ΔT, and time t. When theta=0°, a uniform layer forms whose thickness grows as t at constant F and ΔT. For theta=90°, droplets are formed; at constant F and T, the radius of an isolated droplet grows as t0.23, but, as a result of coalescences, the average droplet radius grows as t0.75. The droplet growth process is self-similar-coalescences simply rescale the distances and leave the basic droplet pattern unaltered.

  4. A Ringdown Breath Analyzer for Diabetes Monitoring: Breath Acetone in Diabetic Patients.

    NASA Astrophysics Data System (ADS)

    Wang, Chuji; Mbi, Armstrong; Shepherd, Mark

    2008-03-01

    It is highly desirable for millions of diabetic patients to have a non-blood, non-invasive, point-of-care device for monitoring daily blood glucose (BG) levels and the adequacy of diabetic treatment and control. Cavity ringdown spectroscopy, due to its unique capability of high sensitivity, fast-response, and relatively low cost for instrumentation, has the potential for medical application through non-invasive analysis of breath biomarkers. We report the first ringdown acetone breath analyzer for clinic testing with diabetic outpatients. The instrument was set in a clinic center and 34 outpatients (24 T1D and 10 T2D) were tested during a four-day period. 10 T1D subjects and 15 nondiabetic persons were tested in our laboratory. Three juvenile-onset T1D subjects were selected for a 24-hr monitoring on the variations of breath acetone and simultaneous BG level. In this talk, we present our research findings including the correlations of breath acetone with BG level and A1C.

  5. Ethylene and ammonia traces measurements from the patients' breath with renal failure via LPAS method

    NASA Astrophysics Data System (ADS)

    Popa, C.; Dutu, D. C. A.; Cernat, R.; Matei, C.; Bratu, A. M.; Banita, S.; Dumitras, D. C.

    2011-11-01

    The application of laser photoacoustic spectroscopy (LPAS) for fast and precise measurements of breath biomarkers has opened up new promises for monitoring and diagnostics in recent years, especially because breath test is a non-invasive method, safe, rapid and acceptable to patients. Our study involved assessment of breath ethylene and breath ammonia levels in patients with renal failure receiving haemodialysis (HD) treatment. Breath samples from healthy subjects and from patients with renal failure were collected using chemically inert aluminized bags and were subsequently analyzed using the LPAS technique. We have found out that the composition of exhaled breath in patients with renal failure contains not only ethylene, but also ammonia and gives valuable information for determining efficacy and endpoint of HD. Analysis of ethylene and ammonia traces from the human breath may provide insight into severity of oxidative stress and metabolic disturbances and may ensure optimal therapy and prevention of pathology at patients on continuous HD.

  6. Standardization of exhaled breath condensate (EBC) collection using a feedback regulated breathing pattern

    EPA Science Inventory

    Collection of exhaled breath condensate (EBC) fluid by cooling of expired breath is a potentially valuable approach for the detection of biomarkers associated with disease or exposure to xenobiotics. EBC is generally collected using unregulated breathing patterns, perceived to el...

  7. Non-invasive 13C-glucose breath test using residual gas analyzer-mass spectrometry: a novel tool for screening individuals with pre-diabetes and type 2 diabetes.

    PubMed

    Ghosh, Chiranjit; Maity, Abhijit; Banik, Gourab D; Som, Suman; Chakraborty, Arpita; Selvan, Chitra; Ghosh, Shibendu; Ghosh, Barnali; Chowdhury, Subhankar; Pradhan, Manik

    2014-09-01

    We report, for the first time, the clinical feasibility of a novel residual gas analyzer mass spectrometry (RGA-MS) method for accurate evaluation of the (13)C-glucose breath test ((13)C-GBT) in the diagnosis of pre-diabetes (PD) and type 2 diabetes mellitus (T2D). In T2D or PD, glucose uptake is impaired and results in blunted isotope enriched (13)CO2 production in exhaled breath samples. Using the Receiver operating characteristics (ROC) curve analysis, an optimal diagnostic cut-off point of the (13)CO2/(12)CO2 isotope ratios expressed as the delta-over-baseline (DOB) value, was determined to be δDOB(13)C‰ = 28.81‰ for screening individuals with non-diabetes controls (NDC) and pre-diabetes (PD), corresponding to a sensitivity of 100% and specificity of 94.4%. We also determined another optimal diagnostic cut-off point of δDOB(13)C‰ = 19.88‰ between individuals with PD and T2D, which exhibited 100% sensitivity and 95.5% specificity. Our RGA-MS methodology for the (13)C-GBT also manifested a typical diagnostic positive and negative predictive value of 96% and 100%, respectively. The diagnostic accuracy, precision and validity of the results were also confirmed by high-resolution optical cavity enhanced integrated cavity output spectroscopy (ICOS) measurements. The δDOB(13)C‰ values measured with RGA-MS method, correlated favourably (R(2) = 0.979) with those determined by the laser based ICOS method. Moreover, we observed that the effects of endogenous CO2 production related to basal metabolic rates in individuals were statistically insignificant (p = 0.37 and 0.73) on the diagnostic accuracy. Our findings suggest that the RGA-MS is a valid and sufficiently robust method for the (13)C-GBT which may serve as an alternative non-invasive point-of-care diagnostic tool for routine clinical practices as well as for large-scale diabetes screening purposes in real-time.

  8. A Study of the Effects of Breath Management Instruction on the Breathing Mode, Knowledge of Breathing, and Performance Skills of College-Level Brass Players.

    ERIC Educational Resources Information Center

    Phillips, Kenneth H.; Sehmann, Karin Harfst

    1990-01-01

    Investigates the effectiveness of breathing instruction on the breath management, performance, and knowledge of breathing among college-level brass musicians. Finds that breathing instruction significantly improved the breath management and knowledge of the breathing for the experimental groups and the musical range of the trombone players in the…

  9. Reliability and Determinants of Self-Evaluation of Breathing Questionnaire (SEBQ) Score: A Symptoms-Based Measure of Dysfunctional Breathing.

    PubMed

    Mitchell, A J; Bacon, C J; Moran, R W

    2016-03-01

    Dysfunctional breathing is characterised by an abnormal breathing pattern leading to respiratory symptoms. The 25-item Self Evaluation of Breathing Questionnaire (SEBQ) has been developed to measure breathing-related symptoms and their severity but lacks thorough evaluation. To determine reproducibility, internal consistency and predictors of SEBQ score, 180 participants completed an online SEBQ with additional demographic and lifestyle questions. Two weeks later, 155 of those repeated SEBQ. Test-retest correlation of the SEBQ was high [intraclass correlation coefficient (3, 1) = 0.89; 95 % CI 0.85-0.92]. There was no difference in SEBQ score between test and retest (15.1 (11.6) [mean (SD)] versus 14.7 (12.4); P = 0.4) and the score showed a typical error (standard error of measurement) of 4.0. Internal consistency was high (Cronbach's α = 0.93), and a single factor structure for items was shown. Smoking status, reported respiratory disease, recent respiratory illness and female gender were positively-associated predictors of SEBQ score, and together explained 25.6 % of score variance (P ≤ 0.001). The SEBQ has high test-retest reproducibility and its score may be predicted by current smoking, chronic respiratory disease, recent respiratory illness and female gender, thus may be a useful clinical screening tool for dysfunctional breathing.

  10. Methacholine bronchial challenge using a dosimeter with controlled tidal breathing.

    PubMed Central

    Nieminen, M M; Lahdensuo, A; Kellomaeki, L; Karvonen, J; Muittari, A

    1988-01-01

    A new inhalation synchronised dosimeter triggered by low inspiratory flow rates has been assessed. The methacholine challenge test using dosimeter nebulisation with controlled tidal breathing was compared with continuous nebulisation using De Vilbiss No 40 nebulisers with deep inhalations in 11 asthmatic subjects. Within subject PD20 FEV1 values were lower with the dosimeter method than with the continuous nebulisation method (geometric means 158 and 588 micrograms). The repeatability of the dosimeter method with controlled tidal breathing was studied in 11 asthmatic subjects, and the 95% range for a single measurement was +/- 0.72 doubling doses of methacholine. The dosimeter method has greater efficacy because aerosol is delivered during the first part of an inhalation, minimising loss of aerosol outside the respiratory tract. The dosimeter technique combined with controlled tidal breathing appears to be a useful method for carrying out standardised non-specific bronchoprovocation tests. Images PMID:3065974

  11. Shortness of Breath

    MedlinePlus

    ... may also order an electrocardiogram (also called an ECG). During this test, your doctor will have you ... down so your heart can be monitored. The ECG machine creates a picture, or tracing, that shows ...

  12. Mathematical and statistical approaches for interpreting biomarker compounds in exhaled human breath

    EPA Science Inventory

    The various instrumental techniques, human studies, and diagnostic tests that produce data from samples of exhaled breath have one thing in common: they all need to be put into a context wherein a posed question can actually be answered. Exhaled breath contains numerous compoun...

  13. Bacterial contamination of anesthesia machines’ internal breathing-circuit-systems

    PubMed Central

    Spertini, Verena; Borsoi, Livia; Berger, Jutta; Blacky, Alexander; Dieb-Elschahawi, Magda; Assadian, Ojan

    2011-01-01

    Background: Bacterial contamination of anesthesia breathing machines and their potential hazard for pulmonary infection and cross-infection among anesthetized patients has been an infection control issue since the 1950s. Disposable equipment and bacterial filters have been introduced to minimize this risk. However, the machines’ internal breathing-circuit-system has been considered to be free of micro-organisms without providing adequate data supporting this view. The aim of the study was to investigate if any micro-organisms can be yielded from used internal machines’ breathing-circuit-system. Based on such results objective reprocessing intervals could be defined. Methods: The internal parts of 40 anesthesia machines’ breathing-circuit-system were investigated. Chi-square test and logistic regression analysis were performed. An on-site process observation of the re-processing sequence was conducted. Results: Bacterial growth was found in 17 of 40 machines (43%). No significant difference was ascertained between the contamination and the processing intervals. The most common contaminants retrieved were coagulase negative Staphylococci, aerobe spore forming bacteria and Micrococcus species. In one breathing-circuit-system, Escherichia coli, and in one further Staphylococcus aureus were yielded. Conclusion: Considering the availability of bacterial filters installed on the outlet of the breathing-circuit-systems, the type of bacteria retrieved and the on-site process observation, we conclude that the contamination found is best explained by a lack of adherence to hygienic measures during and after re-processing of the internal breathing-circuit-system. These results support an extension of the re-processing interval of the anesthesia apparatus longer than the manufacturer’s recommendation of one week. However, the importance of adherence to standard hygienic measures during re-processing needs to be emphasized. PMID:22242095

  14. Submarines, Spacecraft, and Exhaled Breath

    EPA Science Inventory

    The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled b...

  15. Functional analysis and intervention for breath holding.

    PubMed

    Kern, L; Mauk, J E; Marder, T J; Mace, F C

    1995-01-01

    We conducted a functional analysis of breath-holding episodes in a 7-year-old girl with severe mental retardation and Cornelia-de-Lange syndrome. The results showed that breath holding served an operant function, primarily to gain access to attention. The intervention, consisting of extinction, scheduled attention, and use of a picture card communication system, resulted in decreased breath holding.

  16. Changes in breathing while listening to read speech: the effect of reader and speech mode.

    PubMed

    Rochet-Capellan, Amélie; Fuchs, Susanne

    2013-01-01

    The current paper extends previous work on breathing during speech perception and provides supplementary material regarding the hypothesis that adaptation of breathing during perception "could be a basis for understanding and imitating actions performed by other people" (Paccalin and Jeannerod, 2000). The experiments were designed to test how the differences in reader breathing due to speaker-specific characteristics, or differences induced by changes in loudness level or speech rate influence the listener breathing. Two readers (a male and a female) were pre-recorded while reading short texts with normal and then loud speech (both readers) or slow speech (female only). These recordings were then played back to 48 female listeners. The movements of the rib cage and abdomen were analyzed for both the readers and the listeners. Breathing profiles were characterized by the movement expansion due to inhalation and the duration of the breathing cycle. We found that both loudness and speech rate affected each reader's breathing in different ways. Listener breathing was different when listening to the male or the female reader and to the different speech modes. However, differences in listener breathing were not systematically in the same direction as reader differences. The breathing of listeners was strongly sensitive to the order of presentation of speech mode and displayed some adaptation in the time course of the experiment in some conditions. In contrast to specific alignments of breathing previously observed in face-to-face dialog, no clear evidence for a listener-reader alignment in breathing was found in this purely auditory speech perception task. The results and methods are relevant to the question of the involvement of physiological adaptations in speech perception and to the basic mechanisms of listener-speaker coupling.

  17. Changes in breathing while listening to read speech: the effect of reader and speech mode

    PubMed Central

    Rochet-Capellan, Amélie; Fuchs, Susanne

    2013-01-01

    The current paper extends previous work on breathing during speech perception and provides supplementary material regarding the hypothesis that adaptation of breathing during perception “could be a basis for understanding and imitating actions performed by other people” (Paccalin and Jeannerod, 2000). The experiments were designed to test how the differences in reader breathing due to speaker-specific characteristics, or differences induced by changes in loudness level or speech rate influence the listener breathing. Two readers (a male and a female) were pre-recorded while reading short texts with normal and then loud speech (both readers) or slow speech (female only). These recordings were then played back to 48 female listeners. The movements of the rib cage and abdomen were analyzed for both the readers and the listeners. Breathing profiles were characterized by the movement expansion due to inhalation and the duration of the breathing cycle. We found that both loudness and speech rate affected each reader’s breathing in different ways. Listener breathing was different when listening to the male or the female reader and to the different speech modes. However, differences in listener breathing were not systematically in the same direction as reader differences. The breathing of listeners was strongly sensitive to the order of presentation of speech mode and displayed some adaptation in the time course of the experiment in some conditions. In contrast to specific alignments of breathing previously observed in face-to-face dialog, no clear evidence for a listener–reader alignment in breathing was found in this purely auditory speech perception task. The results and methods are relevant to the question of the involvement of physiological adaptations in speech perception and to the basic mechanisms of listener–speaker coupling. PMID:24367344

  18. Interactions between breathing rate and low-frequency fluctuations in blood pressure and cardiac intervals.

    PubMed

    Horsman, H M; Peebles, K C; Tzeng, Y C

    2015-10-01

    Evidence derived from spontaneous measures of cardiovagal baroreflex sensitivity (BRS) suggests that slow breathing at 6 breaths/min augments BRS. However, increases in BRS associated with slow breathing may simply reflect the frequency-dependent nature of the baroreflex rather than the modulation of baroreflex function by changes in breathing rate per se. To test this hypothesis we employed a crossover study design (n = 14) wherein breathing rate and systolic arterial blood pressure (SAP) oscillation induced via the application of oscillating lower body negative pressure (OLBNP) were independently varied at fixed frequencies. Breathing rate was controlled at 6 or 10 breaths/min with the aid of a metronome, and SAP oscillations were driven at 0.06 Hz and 0.1 Hz using OLBNP. The magnitudes of SAP and R-R interval (cardiac period) oscillations were quantified using power spectral analysis, and the transfer function gain between SAP and R-R interval was used to estimate BRS. Linear mixed-effects models were used to examine the main effects and interactions between breathing rate and OLBNP frequency. There was no statistical interaction between breathing and OLBNP frequency (P = 0.59), indicating that the effect of breathing rate on BRS did not differ according to OLBNP frequency (and vice versa). Additionally, there was no main effect for breathing rate (P = 0.28). However, we observed a significant main effect for OLBNP frequency (P = 0.01) consistent with the frequency-dependent nature of baroreflex. These findings suggest that increases in spectral indices of BRS reflect the frequency dependence of the baroreflex and are not due to slow breathing per se.

  19. Waldorf Education: Breathing Creativity

    ERIC Educational Resources Information Center

    Nordlund, Carrie

    2013-01-01

    After 10 years of teaching art in public schools, Carrie Nordlund arrived at a state of query that set in motion her search for alternative approaches to learning. As she was feeling stifled in a seemingly sterile education institution with its overdependence on and pedagogy aimed at standardized tests, she came across a reference to Waldorf…

  20. Drive mechanism for production of simulated human breath

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Lambert, J. W.; Morison, W. B.

    1972-01-01

    Simulated breath drive mechanism was developed as subsystem to breathing metabolic simulator. Mechanism reproduces complete range of human breath rate, breath depth, and breath waveform, as well as independently controlled functional residual capacity. Mechanism was found capable of simulating various individual human breathing characteristics without any changes of parts.

  1. Abdominal breathing manoeuvre reduces passive drag acting on gliding swimmers.

    PubMed

    Maruyama, Yusuke; Yanai, Toshimasa

    2015-01-01

    The purpose of this study was to test the hypothesis that the passive drag acting on a gliding swimmer is reduced if the swimmer adopts an abdominal breathing manoeuvre (expanding the abdominal wall) rather than chest breathing manoeuvre (expanding the rib cage). Eleven male participants participated in this study. A specialised towing machine was used to tow each participant with tension set at various magnitudes and to record time series data of towing velocity. Participants were asked to inhale air by expanding the abdominal wall or the rib cage and to maintain the same body configuration throughout gliding. The steady-state velocity was measured and the coefficient of drag was calculated for each towing trial to compare between the breathing manoeuvres. The results showed that the towing velocity was increased by 0.02 m/s with a towing force of 34.3 N and by 0.06 m/s with a towing force of 98.1 N. The coefficient of drag was reduced by 5% with the abdominal breathing manoeuvre, which was found to be statistically significant (p < 0.05). These results indicate that adopting the abdominal breathing manoeuvre during gliding reduces the passive drag and the hypothesis was supported.

  2. A Portable Real-Time Ringdown Breath Acetone Analyzer: Toward Potential Diabetic Screening and Management.

    PubMed

    Jiang, Chenyu; Sun, Meixiu; Wang, Zhennan; Chen, Zhuying; Zhao, Xiaomeng; Yuan, Yuan; Li, Yingxin; Wang, Chuji

    2016-07-30

    Breath analysis has been considered a suitable tool to evaluate diseases of the respiratory system and those that involve metabolic changes, such as diabetes. Breath acetone has long been known as a biomarker for diabetes. However, the results from published data by far have been inconclusive regarding whether breath acetone is a reliable index of diabetic screening. Large variations exist among the results of different studies because there has been no "best-practice method" for breath-acetone measurements as a result of technical problems of sampling and analysis. In this mini-review, we update the current status of our development of a laser-based breath acetone analyzer toward real-time, one-line diabetic screening and a point-of-care instrument for diabetic management. An integrated standalone breath acetone analyzer based on the cavity ringdown spectroscopy technique has been developed. The instrument was validated by using the certificated gas chromatography-mass spectrometry. The linear fittings suggest that the obtained acetone concentrations via both methods are consistent. Breath samples from each individual subject under various conditions in total, 1257 breath samples were taken from 22 Type 1 diabetic (T1D) patients, 312 Type 2 diabetic (T2D) patients, which is one of the largest numbers of T2D subjects ever used in a single study, and 52 non-diabetic healthy subjects. Simultaneous blood glucose (BG) levels were also tested using a standard diabetic management BG meter. The mean breath acetone concentrations were determined to be 4.9 ± 16 ppm (22 T1D), and 1.5 ± 1.3 ppm (312 T2D), which are about 4.5 and 1.4 times of the one in the 42 non-diabetic healthy subjects, 1.1 ± 0.5 ppm, respectively. A preliminary quantitative correlation (R = 0.56, p < 0.05) between the mean individual breath acetone concentration and the mean individual BG levels does exist in 20 T1D subjects with no ketoacidosis. No direct correlation is observed in T1D subjects, T2D

  3. A Portable Real-Time Ringdown Breath Acetone Analyzer: Toward Potential Diabetic Screening and Management.

    PubMed

    Jiang, Chenyu; Sun, Meixiu; Wang, Zhennan; Chen, Zhuying; Zhao, Xiaomeng; Yuan, Yuan; Li, Yingxin; Wang, Chuji

    2016-01-01

    Breath analysis has been considered a suitable tool to evaluate diseases of the respiratory system and those that involve metabolic changes, such as diabetes. Breath acetone has long been known as a biomarker for diabetes. However, the results from published data by far have been inconclusive regarding whether breath acetone is a reliable index of diabetic screening. Large variations exist among the results of different studies because there has been no "best-practice method" for breath-acetone measurements as a result of technical problems of sampling and analysis. In this mini-review, we update the current status of our development of a laser-based breath acetone analyzer toward real-time, one-line diabetic screening and a point-of-care instrument for diabetic management. An integrated standalone breath acetone analyzer based on the cavity ringdown spectroscopy technique has been developed. The instrument was validated by using the certificated gas chromatography-mass spectrometry. The linear fittings suggest that the obtained acetone concentrations via both methods are consistent. Breath samples from each individual subject under various conditions in total, 1257 breath samples were taken from 22 Type 1 diabetic (T1D) patients, 312 Type 2 diabetic (T2D) patients, which is one of the largest numbers of T2D subjects ever used in a single study, and 52 non-diabetic healthy subjects. Simultaneous blood glucose (BG) levels were also tested using a standard diabetic management BG meter. The mean breath acetone concentrations were determined to be 4.9 ± 16 ppm (22 T1D), and 1.5 ± 1.3 ppm (312 T2D), which are about 4.5 and 1.4 times of the one in the 42 non-diabetic healthy subjects, 1.1 ± 0.5 ppm, respectively. A preliminary quantitative correlation (R = 0.56, p < 0.05) between the mean individual breath acetone concentration and the mean individual BG levels does exist in 20 T1D subjects with no ketoacidosis. No direct correlation is observed in T1D subjects, T2D

  4. A Portable Real-Time Ringdown Breath Acetone Analyzer: Toward Potential Diabetic Screening and Management

    PubMed Central

    Jiang, Chenyu; Sun, Meixiu; Wang, Zhennan; Chen, Zhuying; Zhao, Xiaomeng; Yuan, Yuan; Li, Yingxin; Wang, Chuji

    2016-01-01

    Breath analysis has been considered a suitable tool to evaluate diseases of the respiratory system and those that involve metabolic changes, such as diabetes. Breath acetone has long been known as a biomarker for diabetes. However, the results from published data by far have been inconclusive regarding whether breath acetone is a reliable index of diabetic screening. Large variations exist among the results of different studies because there has been no “best-practice method” for breath-acetone measurements as a result of technical problems of sampling and analysis. In this mini-review, we update the current status of our development of a laser-based breath acetone analyzer toward real-time, one-line diabetic screening and a point-of-care instrument for diabetic management. An integrated standalone breath acetone analyzer based on the cavity ringdown spectroscopy technique has been developed. The instrument was validated by using the certificated gas chromatography-mass spectrometry. The linear fittings suggest that the obtained acetone concentrations via both methods are consistent. Breath samples from each individual subject under various conditions in total, 1257 breath samples were taken from 22 Type 1 diabetic (T1D) patients, 312 Type 2 diabetic (T2D) patients, which is one of the largest numbers of T2D subjects ever used in a single study, and 52 non-diabetic healthy subjects. Simultaneous blood glucose (BG) levels were also tested using a standard diabetic management BG meter. The mean breath acetone concentrations were determined to be 4.9 ± 16 ppm (22 T1D), and 1.5 ± 1.3 ppm (312 T2D), which are about 4.5 and 1.4 times of the one in the 42 non-diabetic healthy subjects, 1.1 ± 0.5 ppm, respectively. A preliminary quantitative correlation (R = 0.56, p < 0.05) between the mean individual breath acetone concentration and the mean individual BG levels does exist in 20 T1D subjects with no ketoacidosis. No direct correlation is observed in T1D subjects, T

  5. Endogenous CO dynamics monitoring in breath by tunable diode laser

    NASA Astrophysics Data System (ADS)

    Kouznetsov, Andrian I.; Stepanov, Eugene V.; Shulagin, Yurii A.; Skrupskii, Vladimir A.

    1996-04-01

    High sensitive CO gas analyzer based on tunable diode laser (TDL) was used as a real time monitor of endogenous carbon monoxide in a set of breath physiology experiments. The measurements of the CO content dynamics in exhaled air with 10 ppb sensitivity were attended with detection of carbon dioxide and O2 in breath, lung ventilation parameters, heart rate and blood analysis using conventional techniques. Variations of endogenous CO in human breath caused by hyperoxia, hypoxia, hyperventilation as well as sport loading were studied in real time. Scattering of the CO variation time constants was observed for different tested persons. Possible reasons for this scattering related with the organisms' physiology peculiarities are discussed.

  6. COPD: When You Learn More, You'll Breathe Better

    MedlinePlus

    ... many as 1 out of 6 people with COPD never smoked. Smoking is the most common cause of COPD—it ... A Simple Breathing Test Everyone at risk for COPD—especially those over age 45 with a history of smoking or those experiencing shortness of breath—should be ...

  7. Changes in CYP2C19 enzyme activity evaluated by the [(13)C]-pantoprazole breath test after co-administration of clopidogrel and proton pump inhibitors following percutaneous coronary intervention and correlation to platelet reactivity.

    PubMed

    Harvey, Adrien; Modak, Anil; Déry, Ugo; Roy, Mélanie; Rinfret, Stéphane; Bertrand, Olivier F; Larose, Éric; Rodés-Cabau, Josep; Barbeau, Gérald; Gleeton, Onil; Nguyen, Can Manh; Proulx, Guy; Noël, Bernard; Roy, Louis; Paradis, Jean-Michel; De Larochellière, Robert; Déry, Jean-Pierre

    2016-03-01

    Dual antiplatelet therapy (DAPT) with clopidogrel and aspirin is used for the prevention of cardiovascular events following percutaneous coronary intervention (PCI). These agents increase the risk of gastrointestinal bleeding. To prevent these events, proton pump inhibitors (PPI) are routinely prescribed. It has been reported that with the exception of pantoprazole and dexlanzoprazole, PPIs can impede conversion of clopidogrel by cytochrome P450 2C19 (CYP2C19) to its active metabolite, a critical step required for clopidogrel efficacy. Changes in CYP2C19 enzyme activity (phenotype) and its correlation with platelet reactivity following PPI therapy has not yet been fully described. In this study we attempted to determine if the [ (13)C]-pantoprazole breath test (Ptz-BT) can evaluate changes in CYP2C19 enzyme activity (phenoconversion) following the administration of PPI in coronary artery disease (CAD) patients treated with DAPT after PCI. Thirty (30) days after successful PCI with stent placement, 59 patients enrolled in the Evaluation of the Influence of Statins and Proton Pump Inhibitors on Clopidogrel Antiplatelet Effects (SPICE) trial (ClinicalTrials.gov Identifier: NCT00930670) were recruited to participate in this sub study. Patients were randomized to one of 4 antacid therapies (omeprazole, esomeprazole. pantoprazole or ranitidine). Subjects were administered the Ptz-BT and platelet function was evaluated by vasodilator-stimulated phosphoprotein (VASP) phosphorylation and light transmittance aggregometry before and 30 d after treatment with antacid therapy. Patients randomized to esomeprazole and omeprazole had greater high on-treatment platelet reactivity and lowering of CYP2C19 enzyme activity at Day 60 after 30 d of PPI therapy. Patients randomized to ranitidine and pantoprazole did not show any changes in platelet activity or CYP 2C19 enzyme activity. In patients treated with esomeprazole and omeprazole, changes in CYP2C19 enzyme activity

  8. [Stahl, Leibniz, Hoffmann and breathing].

    PubMed

    Carvallo, Sarah

    2006-01-01

    At the beginning of the XVIII th century, Wilhelm Gottfried Leibniz and Friedrich Hoffmann criticize Georg Ernst Stahl's medical theory. They differenciate between unsound and true reasonings. Namely, they validate Stahl's definition of breath but extracting it from its animist basis and placing it in an epistemology obeying to the principle of sufficient reason and to the mechanical model. The stahlian discovery consists in understanding breath as a calorific ventilation against the ancient conception; the iatromechanists recognize its accuracy, but they try then to transpose it to a mechanical model of ventilation. Using it in a different epistemological context implies that they analyze the idea of discovery "true" in its contents, but "wrong" in its hypothesis. It impels to examine the epistemology of medical knowledge, as science and therapeutics, and in its links with the other scientific theories. Thus, if Leibniz as philosopher and Hoffmann as doctor consider Stahl's animism so important, it is because its discoveries question the fundamental principles of medicine.

  9. Self-contained breathing apparatus

    NASA Technical Reports Server (NTRS)

    Sullivan, J. L.; Giorgini, E. A.; Simmonds, M. R. (Inventor)

    1976-01-01

    A self-contained breathing apparatus with automatic redundant fluid pressure controls and a facemask mounted low pressure whistle alarm is described. The first stage of the system includes pair of pressure regulators connected in parallel with different outlet pressures, both of which reduce the pressure of the stored supply gas to pressures compatible with the second stage breathing demand regulator. A primary regulator in the first stage delivers a low output pressure to the demand regulator. In the event of a failure closed condition of the primary regulator an automatic transfer valve switches on the backup regulator. A warning that the supply pressure has been depleted is also provided by a supply pressure actuated transfer valve which transfers the output of the first stage pressure regulators from the primary to the backup regulator. The alarm is activated in either the failure closed condition or if the supply pressure is reduced to a dangerously low level.

  10. Running and Breathing in Mammals

    NASA Astrophysics Data System (ADS)

    Bramble, Dennis M.; Carrier, David R.

    1983-01-01

    Mechanical constraints appear to require that locomotion and breathing be synchronized in running mammals. Phase locking of limb and respiratory frequency has now been recorded during treadmill running in jackrabbits and during locomotion on solid ground in dogs, horses, and humans. Quadrupedal species normally synchronize the locomotor and respiratory cycles at a constant ratio of 1:1 (strides per breath) in both the trot and gallop. Human runners differ from quadrupeds in that while running they employ several phase-locked patterns (4:1, 3:1, 2:1, 1:1, 5:2, and 3:2), although a 2:1 coupling ratio appears to be favored. Even though the evolution of bipedal gait has reduced the mechanical constraints on respiration in man, thereby permitting greater flexibility in breathing pattern, it has seemingly not eliminated the need for the synchronization of respiration and body motion during sustained running. Flying birds have independently achieved phase-locked locomotor and respiratory cycles. This hints that strict locomotor-respiratory coupling may be a vital factor in the sustained aerobic exercise of endothermic vertebrates, especially those in which the stresses of locomotion tend to deform the thoracic complex.

  11. Variability in the blood/breath alcohol ratio and implications for evidentiary purposes.

    PubMed

    Jaffe, Dena H; Siman-Tov, Maya; Gopher, Asher; Peleg, Kobi

    2013-09-01

    The breath analyzer is an indispensable tool for identifying alcohol levels among drivers. While numerous studies have shown high correlations between blood and breath alcohol concentrations, most are limited by the study design. This study seeks to assess this relationship by minimizing potential measurement bias, document time from alcohol consumption to testing, and adjusting for potential confounders. A blinded study was performed using conditions closely resembling those in the field. The Draeger 7110 MKIII IL breath analyzer was used to assess breath alcohol concentrations (BrAC). Participants were 61 healthy volunteers aged 21-37 years with body mass index ≤30 and no history of alcoholism. A total of 242 valid blood/breath tests were performed in four test sets. The study results showed a high correlation coefficient between BrAC and blood alcohol concentration (BAC) levels (r = 0.983) with high sensitivity (97%) and specificity (93%). This strong association between the breath analyzer and BAC persisted even after adjustment for various stages of alcohol absorption. These results illustrate the high diagnostic sensitivity of the breath analyzer in field-tested conditions.

  12. Study on the sampling of methadone from exhaled breath.

    PubMed

    Beck, Olof; Sandqvist, Sören; Böttcher, Michael; Eriksen, Paul; Franck, Johan; Palmskog, Göran

    2011-06-01

    This study aimed at develop and validate the procedure for collecting exhaled breath for drug testing. Patients receiving methadone maintenance treatment were recruited for the study. Methadone levels were measured using liquid chromatography- electrospray-tandem mass spectrometry. The sampling device was based on a 47-mm C(18) filter and used under pressure to aid flow through the filter. The mouth was rinsed before sampling, and the device was constructed to protect against any saliva contamination. Methadone was present in breath samples before and after the daily intake of methadone. The mean (± SD) pre-dose level was found to be 135 ± 109 pg/min (n = 48, median 121). The exhaled methadone increased after dose intake. Saliva levels of methadone were high in comparison with exhaled breath levels. Saliva contamination was suspected in about 10% of the collected samples. Similar results were obtained using 1, 3, and 10 min sampling times. The inter- and intraindividual variability were found to be similar and in the order of 50%. Alternative sampling using XAD-2 beads and solid-phase microextraction fiber was found to be possible and enables sampling with low back pressure and with no need for pump assistance. The presented results confirm that breath testing is a new possibility for the detection of drugs of abuse.

  13. Differentiation between genetic mutations of breast cancer by breath volatolomics

    PubMed Central

    Hua, Qing-Ling; Pan, Yue-Yin; Kayal, Haneen; Khoury, Kayan; Liu, Hu; Davies, Michael P.A.; Haick, Hossam

    2015-01-01

    Mapping molecular sub-types in breast cancer (BC) tumours is a rapidly evolving area due to growing interest in, for example, targeted therapy and screening high-risk populations for early diagnosis. We report a new concept for profiling BC molecular sub-types based on volatile organic compounds (VOCs). For this purpose, breath samples were collected from 276 female volunteers, including healthy, benign conditions, ductal carcinoma in situ (DCIS) and malignant lesions. Breath samples were analysed by gas chromatography mass spectrometry (GC-MS) and artificially intelligent nanoarray technology. Applying the non-parametric Wilcoxon/Kruskal-Wallis test, GC-MS analysis found 23 compounds that were significantly different (p < 0.05) in breath samples of BC patients with different molecular sub-types. Discriminant function analysis (DFA) of the nanoarray identified unique volatolomic signatures between cancer and non-cancer cases (83% accuracy in blind testing), and for the different molecular sub-types with accuracies ranging from 82 to 87%, sensitivities of 81 to 88% and specificities of 76 to 96% in leave-one-out cross-validation. These results demonstrate the presence of detectable breath VOC patterns for accurately profiling molecular sub-types in BC, either through specific compound identification by GC-MS or by volatolomic signatures obtained through statistical analysis of the artificially intelligent nanoarray responses. PMID:26540569

  14. Kidney motion during free breathing and breath hold for MR-guided radiotherapy

    NASA Astrophysics Data System (ADS)

    Stam, Mette K.; van Vulpen, Marco; Barendrecht, Maurits M.; Zonnenberg, Bernard A.; Intven, Martijn; Crijns, Sjoerd P. M.; Lagendijk, Jan J. W.; Raaymakers, Bas W.

    2013-04-01

    Current treatments for renal cell carcinoma have a high complication rate due to the invasiveness of the treatment. With the MRI-linac it may be possible to treat renal tumours non-invasively with high-precision radiotherapy. This is expected to reduce complications. To deliver a static dose distribution, radiation gating will be used. In this study the reproducibility and efficiency of free breathing gating and a breath hold treatment of the kidney was investigated. For 15 patients with a renal lesion the kidney motion during 2 min of free breathing and 10 consecutive expiration breath holds was studied with 2D cine MRI. The variability in kidney expiration position and treatment efficiency for gating windows of 1 to 20 mm was measured for both breathing patterns. Additionally the time trend in free breathing and the variation in expiration breath hold kidney position with baseline shift correction was determined. In 80% of the patients the variation in expiration position during free breathing is smaller than 2 mm. No clinically relevant time trends were detected. The variation in expiration breath hold is for all patients larger than the free breathing expiration variation. Gating on free breathing is, for gating windows of 1 to 5 mm more efficient than breath hold without baseline correction. When applying a baseline correction to the breath hold it increases the treatment efficiency. The kidney position is more reproducible in expiration free breathing than non-guided expiration breath hold. For small gating windows it is also more time efficient. Since free breathing also seems more comfortable for the patients it is the preferred breathing pattern for MRI-Linac treatments of the kidney.

  15. Carbon monoxide and water vapor contamination of compressed breathing air for firefighters and divers.

    PubMed

    Austin, C C; Ecobichon, D J; Dussault, G; Tirado, C

    1997-12-12

    Compressed breathing air, used in self-contained breathing apparatus (SCBA) by firefighters and other categories of workers as well as by recreational and commercial divers, is prepared with the aid of high-pressure compressors operating in the range of 5000 psig. There have been reports of unexplained deaths of SCUBA divers and anecdotal accounts of decreased time to exhaustion in firefighters using SCBAs. Compressed breathing air has been found to contain elevated levels of carbon monoxide (CO) and water vapor that are consistent with carboxyhemoglobin (COHb) poisoning and freezing of the user's regulator on the breathing apparatus. The Coburn-Forster-Kane equation (CFK equation) was used to estimate COHb levels at rest and at maximum exercise when exposed to different levels of CO in contaminated breathing air. The results demonstrated that, at maximum exercise, the COHb ranged from 6.0 to 17% with the use of 1 to 4 SCBA cylinders contaminated by 250 ppm CO. Standard operating procedures have been developed at the Montreal Fire Department to minimize the risk of compressed breathing air contamination. Results of the quality analysis/quality control program indicate that implementation of these procedures has improved the quality of the compressed breathing air. Recommendations are made for improvement of the air testing procedures mandated by the Canadian CAN3 180.1-M85 Standard on Compressed Breathing Air and Systems.

  16. Breathing and sense of self: visuo-respiratory conflicts alter body self-consciousness.

    PubMed

    Adler, Dan; Herbelin, Bruno; Similowski, Thomas; Blanke, Olaf

    2014-11-01

    Bodily self-consciousness depends on the processing of interoceptive and exteroceptive signals. It can be disrupted by inducing signal conflicts. Breathing, at the crossroad between interoception and exteroception, should contribute to bodily self-consciousness. We induced visuo-respiratory conflicts in 17 subjects presented with a virtual body or a parallelepidedal object flashing synchronously or asynchronously with their breathing. A questionnaire detected illusory changes in bodily self-consciousness and breathing agency (the feeling of sensing one's breathing command). Changes in self-location were tested by measuring reaction time during mental ball drop (MBD). Synchronous illumination changed the perceived location of breathing (body: p=0.008 vs. asynchronous; object: p=0.013). It resulted in a significant change in breathing agency, but no changes in self-identification. This was corroborated by prolonged MBD reaction time (body: +0.045s, 95%CI [0.013; 0.08], p=0.007). We conclude that breathing modulates bodily self-consciousness. We also conclude that one can induce the irruption of unattended breathing into consciousness without modifying respiratory mechanics or gas exchange.

  17. Qigong--Chinese breathing exercise.

    PubMed

    Koh, T C

    1982-01-01

    Qigong is an ancient Chinese breathing exercise with meditation which is being developed today for therapy of chronic illnesses in the People's Republic of China. It is claimed to cure gastric ulcers, hypertension, anxiety neurosis, otitis media, cancer and has even been used as a form of anaesthesia. Although the physiological effects produced by Qigong resemble those of meditation, there are certain features that are unique and often mysterious. Research in the future may prove Qigong to be a useful adjunct in the practice of medicine.

  18. Breathing

    MedlinePlus Videos and Cool Tools

    ... size of the thoracic cavity and decreases the pressure inside. As a result, air rushes in and ... volume of the thoracic cavity decreases, while the pressure within it increases. As a result, the lungs ...

  19. Shoulder and hip roll differences between breathing and non-breathing conditions in front crawl swimming.

    PubMed

    Psycharakis, Stelios G; McCabe, Carla

    2011-06-01

    The effects of breathing on body roll have been previously investigated for the roll of the whole trunk only. The purposes of this study were: to calculate separately the shoulder roll (SR) and hip roll (HR) of swimmers during front crawl for non-breathing and preferred-side breathing conditions; to assess the differences in the magnitude and temporal characteristics of these variables between non-breathing and preferred-side breathing conditions; and to examine their association with swimming performance (indicated by swimming speed). Twelve male swimmers who competed at national and international level performed two maximum 25 m front crawl trials: one non-breathing and one with breathing to their preferred side. Performance was recorded with four below and two above water synchronised cameras. SR and HR in both trials were calculated for the breathing and non-breathing sides. The timings of SR and HR peaks to each side and at the positions of neutral roll were also calculated. Swimming speed was significantly slower in the breathing trial (p < 0.01). Swimmers rolled their shoulders and hips to the breathing side significantly more in the breathing than in the non-breathing trial (SR: p < 0.01; HR: p = 0.03). Nevertheless, there were no significant differences in the overall SR or HR between these trials. In the breathing trial, SR was higher in the breathing than in the non-breathing side (p < 0.01) but HR was not significantly different (p = 0.07). There was no evidence to suggest that temporal characteristics of SR or HR were associated with swimming performance.

  20. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American National Standards... 42 Public Health 1 2013-10-01 2013-10-01 false Compressed breathing gas and liquefied breathing... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed...

  1. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American National Standards... 42 Public Health 1 2012-10-01 2012-10-01 false Compressed breathing gas and liquefied breathing... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed...

  2. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American National Standards... 42 Public Health 1 2014-10-01 2014-10-01 false Compressed breathing gas and liquefied breathing... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed...

  3. Lung function measurement with multiple-breath-helium washout system.

    PubMed

    Wang, J-Y; Suddards, M E; Mellor, C J; Owers-Bradley, J R

    2013-04-01

    Multiple-breath-washout (MBW) measurements are regarded as a sensitive technique which can reflect the ventilation inhomogeneity of respiratory airways. Typically nitrogen is used as the tracer gas and is washed out by pure oxygen in multiple-breath-nitrogen washout (MBNW) tests. In this study, instead of using nitrogen, (4)He is used as the tracer gas with smaller gas density which may be able to reach deeper into our lungs in a given time and the helium washout results may be more sensitive to the ventilation inhomogeneity in small airways. A multiple-breath-helium-washout (MBHW) system developed for the lung function study is also presented. Quartz tuning forks with a resonance frequency of 32,768Hz have been used for detecting the change of the respiratory gas density. The resonance frequency of the quartz tuning fork decreases linearly with increasing density of the surrounding gas. Knowing the CO2 concentration from the infrared carbon dioxide detector, the helium concentration can be determined. Results from 14 volunteers (3 mild asthmatics, 4 tobacco smokers, 1 with asthma history, 1 with COPD history, 5 normal) have shown that mild asthmatics have higher ventilation inhomogeneity in either conducting or acinar airways (or both). A feature has been found in washout curve of single breaths from 4 tobacco smokers with different length of smoking history which may indicate the early stage of respiratory ventilation inhomogeneity in acinar airways.

  4. Medical Diagnostic Breath Analysis by Cavity Ring Down Spectroscopy

    NASA Astrophysics Data System (ADS)

    Guss, Joseph S.; Metsälä, Markus; Halonen, Lauri

    2009-06-01

    Certain medical conditions give rise to the presence of chemicals in the bloodstream. These chemicals - known as biomarkers - may also be present in low concentrations in human breath. Cavity ring down spectroscopy possesses the requisite selectivity and sensitivity to detect such biomarkers in the congested spectrum of a breath sample. The ulcer-causing bacterium, Helicobacter pylori, is a prolific producer of the enzyme urease, which catalyses the breakdown of urea ((NH_2)_2CO) in the stomach as follows: (NH_2)_2CO + H_2O ⟶ CO_2 + 2NH_3 Currently, breath tests seeking altered carbon-isotope ratios in exhaled CO_2 after the ingestion of ^{13}C- or ^{14}C-labeled urea are used to diagnose H. pylori infection. We present recent results from an ongoing collaboration with Tampere Area University Hospital. The study involves 100 patients (both infected and uninfected) and concerns the possible correlation between the bacterial infection and breath ammonia. D. Y. Graham, P. D. Klein, D. J. Evans, Jr, D. G. Evans, L. C. Alpert, A. R. Opekun, T. W. Boutton, Lancet 1(8543), 1174-7 March 1987.

  5. Respiration-correlated treatment delivery using feedback-guided breath hold: A technical study

    SciTech Connect

    Nelson, Christopher; Starkschall, George; Balter, Peter; Fitzpatrick, Mathew J.; Antolak, John A.; Tolani, Naresh; Prado, Karl

    2005-01-01

    Respiratory motion causes movement of internal structures in the thorax and abdomen, making accurate delivery of radiation therapy to tumors in those areas a challenge. To reduce the uncertainties caused by this motion, we have developed feedback-guided breath hold (FGBH), a novel delivery technique in which radiation is delivered only during a voluntary breath hold that is sustained for as long as the patient feels comfortable. Here we present the technical aspects of FGBH, which involve (1) fabricating the hardware so the respiratory trace can be displayed to the patient, (2) assembling a delay box to be used as a breath-hold detector, and (3) performing quality control tests to ensure that FGBH can be delivered accurately and safely. A commercial respiratory tracking system that uses an external fiducial to monitor abdominal wall motion generates and displays the breathing trace and specific positions in the breathing cycle where a breath hold needs to occur. Hardware was developed to present this display to the patient in the treatment position. Patients view the presentation either on a liquid crystal display or through a pair of virtual reality goggles. Using the respiratory trace as a visual aid, the patient performs a breath hold so that the position representing the location of a fiducial is held within a specified gating window. A delay box was fabricated to differentiate between gating signals received during free breathing and those received during breath hold, allowing radiation delivery only when the fiducial was within the breath-hold gating window. A quality control analysis of the gating delay box and the integrated system was performed to ensure that all of the hardware and components were ready for clinical use.

  6. Clinical utility of breath ammonia for evaluation of ammonia physiology in healthy and cirrhotic adults.

    PubMed

    Spacek, Lisa A; Mudalel, Matthew; Tittel, Frank; Risby, Terence H; Solga, Steven F

    2015-12-14

    Blood ammonia is routinely used in clinical settings to assess systemic ammonia in hepatic encephalopathy and urea cycle disorders. Despite its drawbacks, blood measurement is often used as a comparator in breath studies because it is a standard clinical test. We sought to evaluate sources of measurement error and potential clinical utility of breath ammonia compared to blood ammonia. We measured breath ammonia in real time by quartz enhanced photoacoustic spectrometry and blood ammonia in 10 healthy and 10 cirrhotic participants. Each participant contributed 5 breath samples and blood for ammonia measurement within 1 h. We calculated the coefficient of variation (CV) for 5 breath ammonia values, reported medians of healthy and cirrhotic participants, and used scatterplots to display breath and blood ammonia. For healthy participants, mean age was 22 years (±4), 70% were men, and body mass index (BMI) was 27 (±5). For cirrhotic participants, mean age was 61 years (±8), 60% were men, and BMI was 31 (±7). Median blood ammonia for healthy participants was within normal range, 10 μmol L(-1) (interquartile range (IQR), 3-18) versus 46 μmol L(-1) (IQR, 23-66) for cirrhotic participants. Median breath ammonia was 379 pmol mL(-1) CO2 (IQR, 265-765) for healthy versus 350 pmol mL(-1) CO2 (IQR, 180-1013) for cirrhotic participants. CV was 17  ±  6%. There remains an important unmet need in the evaluation of systemic ammonia, and breath measurement continues to demonstrate promise to fulfill this need. Given the many differences between breath and blood ammonia measurement, we examined biological explanations for our findings in healthy and cirrhotic participants. We conclude that based upon these preliminary data breath may offer clinically important information this is not provided by blood ammonia.

  7. Clinical utility of breath ammonia for evaluation of ammonia physiology in healthy and cirrhotic adults

    PubMed Central

    Spacek, Lisa A; Mudalel, Matthew; Tittel, Frank; Risby, Terence H; Solga, Steven F

    2016-01-01

    Blood ammonia is routinely used in clinical settings to assess systemic ammonia in hepatic encephalopathy and urea cycle disorders. Despite its drawbacks, blood measurement is often used as a comparator in breath studies because it is a standard clinical test. We sought to evaluate sources of measurement error and potential clinical utility of breath ammonia compared to blood ammonia. We measured breath ammonia in real time by quartz enhanced photoacoustic spectrometry and blood ammonia in 10 healthy and 10 cirrhotic participants. Each participant contributed 5 breath samples and blood for ammonia measurement within 1 h. We calculated the coefficient of variation (CV) for 5 breath ammonia values, reported medians of healthy and cirrhotic participants, and used scatterplots to display breath and blood ammonia. For healthy participants, mean age was 22 years (±4), 70% were men, and body mass index (BMI) was 27 (±5). For cirrhotic participants, mean age was 61 years (±8), 60% were men, and BMI was 31 (±7). Median blood ammonia for healthy participants was within normal range, 10 μmol L−1 (interquartile range (IQR), 3–18) versus 46 μmol L−1 (IQR, 23–66) for cirrhotic participants. Median breath ammonia was 379 pmol mL−1 CO2 (IQR, 265–765) for healthy versus 350 pmol mL−1 CO2 (IQR, 180–1013) for cirrhotic participants. CV was 17 ± 6%. There remains an important unmet need in the evaluation of systemic ammonia, and breath measurement continues to demonstrate promise to fulfill this need. Given the many differences between breath and blood ammonia measurement, we examined biological explanations for our findings in healthy and cirrhotic participants. We conclude that based upon these preliminary data breath may offer clinically important information this is not provided by blood ammonia. PMID:26658550

  8. Breath isoprene concentrations in persons undergoing general anesthesia and in healthy volunteers.

    PubMed

    Hornuss, Cyrill; Zagler, Armin; Dolch, Michael E; Wiepcke, Dirk; Praun, Siegfried; Boulesteix, Anne-Laure; Weis, Florian; Apfel, Christian C; Schelling, Gustav

    2012-12-01

    Human breath contains an abundance of volatile organic compounds (VOCs). Analysis of breath VOC may be used for diagnosis of various diseases or for on-line monitoring in anesthesia and intensive care. However, VOC concentrations largely depend on the breath sampling method and have a large inter-individual variability. For the development of breath tests, the influence of breath sampling methods and study subject characteristics on VOC concentrations has to be known. Therefore, we investigated the VOC isoprene in 62 study subjects during anesthesia and 16 spontaneously breathing healthy volunteers to determine (a) the influence of artificial and spontaneous ventilation and (b) the influence of study subject characteristics on breath isoprene concentrations. We used ion molecule reaction mass spectrometry for high-resolution breath-by-breath analysis of isoprene. We found that persons during anesthesia had significantly increased inspiratory and end-expiratory isoprene breath concentrations. Measured isoprene concentrations (median [first quartile-third quartile]) were in the anesthesia group: 54 [40-79] ppb (inspiratory) and 224 [171-309] ppb (end-expiratory), volunteer group: 14 [11-17] ppb (inspiratory) and 174 [124-202] ppb (end-expiratory). Higher end-tidal CO(2) concentrations in ventilated subjects were associated with higher expiratory isoprene levels. Furthermore, inspiratory and end-expiratory isoprene concentrations were correlated during anesthesia (r = 0.603, p < 0.001). Multivariate analysis showed that men had significantly higher end-expiratory isoprene concentrations than women. Rebreathing of isoprene from the anesthesia machine possibly accounts for the observed increase in isoprene in the anesthesia group.

  9. Protective supplied breathing air garment

    DOEpatents

    Childers, E.L.; Hortenau, E.F. von.

    1984-07-10

    A breathing air garment is disclosed for isolating a wearer from hostile environments containing toxins or irritants includes a suit and a separate head protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit rear torso panel permits access into the suit and is sealed with an adhesive sealing flap. 17 figs.

  10. Protective supplied breathing air garment

    DOEpatents

    Childers, Edward L.; von Hortenau, Erik F.

    1984-07-10

    A breathing air garment for isolating a wearer from hostile environments containing toxins or irritants includes a suit and a separate head protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit rear torso panel permits access into the suit and is sealed with an adhesive sealing flap.

  11. An evaluation of Fourier transform infrared (FTIR) spectroscopy for detecting organic solvents in expired breath.

    PubMed

    Yost, Michael G; Rose, Martin A; Morgan, Michael S

    2003-03-01

    The aim of this study was to test the performance of gas-phase FTIR analysis on human breath samples. Ten volatile organic compounds (VOC) were examined for applicability to FTIR spectroscopy (ethanol, ethylbenzene, n-hexane, methyl ethyl ketone, methyl tert-butyl ether, m-xylene, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and toluene). Three sets of detection limits (LOD) were determined for comparison. LOD(1) were generated from partial least squares (PLS) calibration methods using spectroscopic software, LOD(2) from spiked breath samples, and LOD(3) from blank breath samples. Mixed expired breath samples from four subjects were spiked at varying levels with four different VOC (hexane, methyl ethyl ketone, m-xylene and 1,1,1-trichloroethane) to validate spectral data and test overall accuracy. Breath samples spiked with m-xylene also were validated by GC/FID analysis. PLS-derived LOD(1) ranged from 0.06-2.47 ppm. Spiked breath sample LOD(2) ranged from 0.52-1.21 ppm. Blank breath LOD(3) measurements ranged from 0.17-1.70 ppm, except for ethanol, which had an LOD of 11.2 ppm. Predicted concentrations for carbon dioxide (slope = 1.06), m-xylene (slopes = 1.19, 1.21), and methyl ethyl ketone (slope = 0.93) were fairly accurate, while concentrations were underpredicted for n-hexane (slope = 0.69) and 1,1,1-trichloroethane (slopes = 0.58-0.66). PMID:12573961

  12. Submarines, spacecraft and exhaled breath.

    PubMed

    Pleil, Joachim D; Hansel, Armin

    2012-03-01

    Foreword The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled breath. What may have escaped our notice is a complementary field of research that explores the creation and maintenance of artificial atmospheres practised by the submarine air monitoring and air purification (SAMAP) community. SAMAP is comprised of manufacturers, researchers and medical professionals dealing with the engineering and instrumentation to support human life in submarines and spacecraft (including shuttlecraft and manned rockets, high-altitude aircraft, and the International Space Station (ISS)). Here, the immediate concerns are short-term survival and long-term health in fairly confined environments where one cannot simply 'open the window' for fresh air. As such, one of the main concerns is air monitoring and the main sources of contamination are CO(2) and other constituents of human exhaled breath. Since the inaugural meeting in 1994 in Adelaide, Australia, SAMAP meetings have been held every two or three years alternating between the North American and European continents. The meetings are organized by Dr Wally Mazurek (a member of IABR) of the Defense Systems Technology Organization (DSTO) of Australia, and individual meetings are co-hosted by the navies of the countries in which they are held. An overriding focus at SAMAP is life support (oxygen availability and carbon dioxide removal). Certainly, other air constituents are also important; for example, the closed environment of a submarine or the ISS can build up contaminants from consumer products, cooking, refrigeration, accidental fires, propulsion and atmosphere maintenance. However, the most immediate concern is sustaining human metabolism: removing exhaled CO(2) and replacing metabolized O(2). Another

  13. Submarines, spacecraft and exhaled breath.

    PubMed

    Pleil, Joachim D; Hansel, Armin

    2012-03-01

    Foreword The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled breath. What may have escaped our notice is a complementary field of research that explores the creation and maintenance of artificial atmospheres practised by the submarine air monitoring and air purification (SAMAP) community. SAMAP is comprised of manufacturers, researchers and medical professionals dealing with the engineering and instrumentation to support human life in submarines and spacecraft (including shuttlecraft and manned rockets, high-altitude aircraft, and the International Space Station (ISS)). Here, the immediate concerns are short-term survival and long-term health in fairly confined environments where one cannot simply 'open the window' for fresh air. As such, one of the main concerns is air monitoring and the main sources of contamination are CO(2) and other constituents of human exhaled breath. Since the inaugural meeting in 1994 in Adelaide, Australia, SAMAP meetings have been held every two or three years alternating between the North American and European continents. The meetings are organized by Dr Wally Mazurek (a member of IABR) of the Defense Systems Technology Organization (DSTO) of Australia, and individual meetings are co-hosted by the navies of the countries in which they are held. An overriding focus at SAMAP is life support (oxygen availability and carbon dioxide removal). Certainly, other air constituents are also important; for example, the closed environment of a submarine or the ISS can build up contaminants from consumer products, cooking, refrigeration, accidental fires, propulsion and atmosphere maintenance. However, the most immediate concern is sustaining human metabolism: removing exhaled CO(2) and replacing metabolized O(2). Another

  14. How Does a Hopping Kangaroo Breathe?

    ERIC Educational Resources Information Center

    Giuliodori, Mauricio J.; Lujan, Heidi L.; Janbaih, Hussein; DiCarlo, Stephen E.

    2010-01-01

    We developed a model to demonstrate how a hopping kangaroo breathes. Interestingly, a kangaroo uses less energy to breathe while hopping than while standing still. This occurs, in part, because rather than using muscle power to move air into and out of the lungs, air is pulled into (inspiration) and pushed out of (expiration) the lungs as the…

  15. EXHALED BREATH ANALYSIS FOR HUMAN EXPOSURE RESEARCH

    EPA Science Inventory

    Exhaled breath collection and analysis has historically been used in environmental research studies to characterize exposures to volatile organic compounds. The use of this approach is based on the fact that many compounds present in blood are reflected in the breath, and that...

  16. Rapid eye movement sleep in breath holders.

    PubMed

    Kohyama, J; Hasegawa, T; Shimohira, M; Fukumizu, M; Iwakawa, Y

    2000-07-01

    One-night polysomnography was performed on seven subjects suffering from breath-holding spells, including one whose death was suggested to be a consequence of a breath-holding spell. The fatal case showed no rapid eye movements (REMs) during REM sleep, although he exhibited REMs during wakefulness. The average numbers of both REMs and bursts of REMs in REM sleep in the other six breath holders were significantly lower than those in age-matched controls. The breath holders showed no airway obstruction, desaturation, or sleep fragmentation. Since the rapid ocular activity in REM sleep is generated in the brain stem, we hypothesized that a functional brainstem disturbance is involved in the occurrence of breath-holding spells.

  17. Breathing evaluation and retraining in manual therapy.

    PubMed

    McLaughlin, Laurie

    2009-07-01

    Patients with back and neck pain commonly seek body work yet there are some who do not experience full recovery with the typical tool kit of manual therapy, education and exercise, suggesting the need for additional clinical approaches. Epidemiological literature linking back pain with breathing difficulties suggests one possibility. Altered motor control associated with back and neck pain appears to negatively impact breathing mechanics, which may have negative consequences on respiratory chemistry. Changes in respiratory chemistry can have profound effects on body system function. Altered breathing has been recognized for many years as a potential source of a wide variety of unexplained symptoms. There has been controversy around accurate diagnosis with symptoms and questionnaires often being the only methods used. Capnography, which is routinely used in critical care settings, offers an objective measure of respiratory chemistry providing physiological data on which to base a diagnosis of poor breathing. Capnography can also be used as biofeedback to guide breathing retraining.

  18. Computer simulation of breathing systems for divers

    SciTech Connect

    Sexton, P.G.; Nuckols, M.L.

    1983-02-01

    A powerful new tool for the analysis and design of underwater breathing gas systems is being developed. A versatile computer simulator is described which makes possible the modular ''construction'' of any conceivable breathing gas system from computer memory-resident components. The analysis of a typical breathing gas system is demonstrated using this simulation technique, and the effects of system modifications on performance of the breathing system are shown. This modeling technique will ultimately serve as the foundation for a proposed breathing system simulator under development by the Navy. The marriage of this computer modeling technique with an interactive graphics system will provide the designer with an efficient, cost-effective tool for the development of new and improved diving systems.

  19. Slow breathing influences cardiac autonomic responses to postural maneuver: Slow breathing and HRV.

    PubMed

    Vidigal, Giovanna Ana de Paula; Tavares, Bruna S; Garner, David M; Porto, Andrey A; Carlos de Abreu, Luiz; Ferreira, Celso; Valenti, Vitor E

    2016-05-01

    Chronic slow breathing has been reported to improve Heart Rate Variability (HRV) in patients with cardiovascular disorders. However, it is not clear regarding its acute effects on HRV responses on autonomic analysis. We evaluated the acute effects of slow breathing on cardiac autonomic responses to postural change manoeuvre (PCM). The study was conducted on 21 healthy male students aged between 18 and 35 years old. In the control protocol, the volunteer remained at rest seated for 15 min under spontaneous breathing and quickly stood up within 3 s and remained standing for 15 min. In the slow breathing protocol, the volunteer remained at rest seated for 10 min under spontaneous breath, then performed slow breathing for 5 min and rapidly stood up within 3 s and remained standing for 15 min. Slow breathing intensified cardiac autonomic responses to postural maneuver. PMID:27157952

  20. Biomechanical interpretation of a free-breathing lung motion model

    NASA Astrophysics Data System (ADS)

    Zhao, Tianyu; White, Benjamin; Moore, Kevin L.; Lamb, James; Yang, Deshan; Lu, Wei; Mutic, Sasa; Low, Daniel A.

    2011-12-01

    The purpose of this paper is to develop a biomechanical model for free-breathing motion and compare it to a published heuristic five-dimensional (5D) free-breathing lung motion model. An ab initio biomechanical model was developed to describe the motion of lung tissue during free breathing by analyzing the stress-strain relationship inside lung tissue. The first-order approximation of the biomechanical model was equivalent to a heuristic 5D free-breathing lung motion model proposed by Low et al in 2005 (Int. J. Radiat. Oncol. Biol. Phys. 63 921-9), in which the motion was broken down to a linear expansion component and a hysteresis component. To test the biomechanical model, parameters that characterize expansion, hysteresis and angles between the two motion components were reported independently and compared between two models. The biomechanical model agreed well with the heuristic model within 5.5% in the left lungs and 1.5% in the right lungs for patients without lung cancer. The biomechanical model predicted that a histogram of angles between the two motion components should have two peaks at 39.8° and 140.2° in the left lungs and 37.1° and 142.9° in the right lungs. The data from the 5D model verified the existence of those peaks at 41.2° and 148.2° in the left lungs and 40.1° and 140° in the right lungs for patients without lung cancer. Similar results were also observed for the patients with lung cancer, but with greater discrepancies. The maximum-likelihood estimation of hysteresis magnitude was reported to be 2.6 mm for the lung cancer patients. The first-order approximation of the biomechanical model fit the heuristic 5D model very well. The biomechanical model provided new insights into breathing motion with specific focus on motion trajectory hysteresis.

  1. Sigh-induced changes of breathing pattern in preterm infants

    PubMed Central

    Jost, Kerstin; Latzin, Philipp; Fouzas, Sotirios; Proietti, Elena; Delgado-Eckert, Edgar W; Frey, Urs; Schulzke, Sven M

    2015-01-01

    Sighs are thought to play an important role in control of breathing. It is unclear how sighs are triggered, and whether preterm birth and lung disease influence breathing pattern prior to and after a sigh in infants. To assess whether frequency, morphology, size, and short-term variability in tidal volume (VT) before, during, and after a sigh are influenced by gestational age at birth and lung disease (bronchopulmonary dysplasia, BPD) in former preterm infants and healthy term controls measured at equivalent postconceptional age (PCA). We performed tidal breathing measurements in 143 infants during quiet natural sleep at a mean (SD) PCA of 44.8 (1.3) weeks. A total of 233 sighs were analyzed using multilevel, multivariable regression. Sigh frequency in preterm infants increased with the degree of prematurity and severity of BPD, but was not different from that of term controls when normalized to respiratory rate. After a sigh, VT decreased remarkably in all infants (paired t-test: P < 0.001). There was no major effect of prematurity or BPD on various indices of sigh morphology and changes in VT prior to or after a sigh. Short-term variability in VT modestly increased with maturity at birth and infants with BPD showed an earlier return to baseline variability in VT following a sigh. In early infancy, sigh-induced changes in breathing pattern are moderately influenced by prematurity and BPD in preterm infants. The major determinants of sigh-related breathing pattern in these infants remain to be investigated, ideally using a longitudinal study design. PMID:26564066

  2. Differences between roadside and subsequent evidential breath alcohol results and their forensic significance.

    PubMed

    Gullberg, R G

    1991-07-01

    Breath alcohol measurements for forensic purposes are typically not made at the time of a driving incident but at some later time. Therefore, the magnitude of variation in breath alcohol concentration (BrAC) following the time of arrest is of concern. The use of roadside preliminary breath test (PBT) instruments can provide data on BrAC closer to the time of a driving incident and allow for comparison with later evidential analysis. This retrospective study evaluates two distributions (N = 968): differences between PBT results and the first evidential breath test (PBT-BrAC1) and differences between two (duplicate) evidential breath alcohol tests (BrAC1-BrAC2). The two distributions were shown to vary from each other and from the normal with statistical significance (p less than .05). The PBT-BrAC1 distribution had greater variability (SD = .025) than the BrAC1-BrAC2 distribution (SD = .010). An important result was that the PBT was equal to (within duplicate sampling variability) or greater than BrAC1 in approximately 85.5% of the cases. The remaining 14.5% could not be explained by sampling variability within the duplicate test distribution. The variability in both distributions typically exceeds the normally accepted alcohol elimination rates. The conclusion is that differences between roadside and subsequent evidential breath results cannot be attributed solely to absorption or elimination kinetics. Intra-individual breath sample differences can be large and thus obscure the accurate evaluation of absorption and elimination rates. Breath tests conducted within approximately 2 hours of driving will reflect, within experimental uncertainty, the BrAC at the time of driving.

  3. Treatment of Chronic Breath-Holding in an Adult with Severe Mental Retardation: A Clinical Case Study

    ERIC Educational Resources Information Center

    Reed, Derek D.; Martens, Brian K.

    2008-01-01

    We describe a clinical case study surrounding the behavioral assessment and operant treatment of, an adult with severe mental retardation who engaged in chronic breath-holding. In this clinical case, previous neurological and medical testing had ruled out biological bases for the individual's breath-holding. A functional behavioral assessment…

  4. The indoor air we breathe.

    PubMed Central

    Oliver, L C; Shackleton, B W

    1998-01-01

    Increasingly recognized as a potential public health problem since the outbreak of Legionnaire's disease in Philadelphia in 1976, polluted indoor air has been associated with health problems that include asthma, sick building syndrome, multiple chemical sensitivity, and hypersensitivity pneumonitis. Symptoms are often nonspecific and include headache, eye and throat irritation, chest tightness and shortness of breath, and fatigue. Air-borne contaminants include commonly used chemicals, vehicular exhaust, microbial organisms, fibrous glass particles, and dust. Identified causes include defective building design and construction, aging of buildings and their ventilation systems, poor climate control, inattention to building maintenance. A major contributory factor is the explosion in the use of chemicals in building construction and furnishing materials over the past four decades. Organizational issues and psychological variables often contribute to the problem and hinder its resolution. This article describes the health problems related to poor indoor air quality and offers solutions. Images p398-a p399-a PMID:9769764

  5. The indoor air we breathe.

    PubMed

    Oliver, L C; Shackleton, B W

    1998-01-01

    Increasingly recognized as a potential public health problem since the outbreak of Legionnaire's disease in Philadelphia in 1976, polluted indoor air has been associated with health problems that include asthma, sick building syndrome, multiple chemical sensitivity, and hypersensitivity pneumonitis. Symptoms are often nonspecific and include headache, eye and throat irritation, chest tightness and shortness of breath, and fatigue. Air-borne contaminants include commonly used chemicals, vehicular exhaust, microbial organisms, fibrous glass particles, and dust. Identified causes include defective building design and construction, aging of buildings and their ventilation systems, poor climate control, inattention to building maintenance. A major contributory factor is the explosion in the use of chemicals in building construction and furnishing materials over the past four decades. Organizational issues and psychological variables often contribute to the problem and hinder its resolution. This article describes the health problems related to poor indoor air quality and offers solutions.

  6. Breath acetone monitoring by portable Si:WO3 gas sensors

    PubMed Central

    Righettoni, Marco; Tricoli, Antonio; Gass, Samuel; Schmid, Alex; Amann, Anton; Pratsinis, Sotiris E.

    2013-01-01

    Breath analysis has the potential for early stage detection and monitoring of illnesses to drastically reduce the corresponding medical diagnostic costs and improve the quality of life of patients suffering from chronic illnesses. In particular, the detection of acetone in the human breath is promising for non-invasive diagnosis and painless monitoring of diabetes (no finger pricking). Here, a portable acetone sensor consisting of flame-deposited and in situ annealed, Si-doped epsilon-WO3 nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone (~20 ppb) with short response (10–15 s) and recovery times (35–70 s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80–90%) as in the human breath. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques. PMID:22790702

  7. Comparison of impedance and inductance ventilation sensors on adults during breathing, motion, and simulated airway obstruction.

    PubMed

    Cohen, K P; Ladd, W M; Beams, D M; Sheers, W S; Radwin, R G; Tompkins, W J; Webster, J G

    1997-07-01

    The goal of this study was to compare the relative performance of two noninvasive ventilation sensing technologies on adults during artifacts. We recorded changes in transthoracic impedance and cross-sectional area of the abdomen (abd) and rib cage (rc) using impedance pneumography (IP) and respiratory inductance plethysmography (RIP) on ten adult subjects during natural breathing, motion artifact, simulated airway obstruction, yawning, snoring, apnea, and coughing. We used a pneumotachometer to measure air flow and tidal volume as the standard. We calibrated all sensors during natural breathing, and performed measurements during all maneuvers without changing the calibration parameters. No sensor provided the most-accurate measure of tidal volume for all maneuvers. Overall, the combination of inductance sensors [RIP(sum)] calibrated during an isovolume maneuver had a bias (weighted mean difference) as low or lower than all individual sensors and all combinations of sensors. The IP(rc) sensor had a bias as low or lower than any individual sensor. The cross-correlation coefficient between sensors was high during natural breathing, but decreased during artifacts. The cross correlation between sensor pairs was lower during artifacts without breathing than it was during maneuvers with breathing for four different sensor combinations. We tested a simple breath-detection algorithm on all sensors and found that RIP(sum) resulted in the fewest number of false breath detections, with sensitivity of 90.8% and positive predictivity of 93.6%.

  8. Breath acetone monitoring by portable Si:WO3 gas sensors.

    PubMed

    Righettoni, Marco; Tricoli, Antonio; Gass, Samuel; Schmid, Alex; Amann, Anton; Pratsinis, Sotiris E

    2012-08-13

    Breath analysis has the potential for early stage detection and monitoring of illnesses to drastically reduce the corresponding medical diagnostic costs and improve the quality of life of patients suffering from chronic illnesses. In particular, the detection of acetone in the human breath is promising for non-invasive diagnosis and painless monitoring of diabetes (no finger pricking). Here, a portable acetone sensor consisting of flame-deposited and in situ annealed, Si-doped epsilon-WO(3) nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone (∼20ppb) with short response (10-15s) and recovery times (35-70s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80-90%) as in the human breath. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques. PMID:22790702

  9. Evaluation of oxygen saturation by pulse-oximetry in mouth breathing patients.

    PubMed

    Niaki, Esfandiar Akhavan; Chalipa, Javad; Taghipoor, Elahe

    2010-01-01

    Mouth breathing might not always result in hypoxia, but can contribute to it. The aim of the present study was to determine the effect of mouth breathing on hypoxia. Based on a pilot study, 323 patients with mouth breathing were selected. Assessment of mouth breathing was based on clinical examination and questionnaires filled out by patients and their companions. The patients were also examined for further oral findings that could be attributable to mouth breathing. Oxygen saturation of each case was measured by means of a pulse oximetry device. The level of 95% saturation was set as the limit, under which the patient was considered hypoxemic. Acquired data was analyzed for descriptive data and frequency and also by means of the Chi-square and Spearman's correlation coefficient tests. 34.6% of the cases had normal O2 saturation. 65.4% of cases were hypoxemic (saturation level was below 95% in 42.8% and 95% in 22.6%). Most of the mouth breathing patients were male who were also more hypoxemic. A weak inverse relationship existed between the age of the patients and Oxygen saturation. Deep palatal vaults (29.4%) and gingival hyperplasia (29.2%) were the most frequent intraoral findings. Concerning the effects of hypoxia on body systems, the use of pulse oximetry in suspected mouth breathing patients could be recommended in routine oral and dental examinations.

  10. How does breathing frequency affect the performance of an N95 filtering facepiece respirator and a surgical mask against surrogates of viral particles?

    PubMed

    He, Xinjian; Reponen, Tiina; McKay, Roy; Grinshpun, Sergey A

    2014-01-01

    Breathing frequency (breaths/min) differs among individuals and levels of physical activity. Particles enter respirators through two principle penetration pathways: faceseal leakage and filter penetration. However, it is unknown how breathing frequency affects the overall performance of N95 filtering facepiece respirators (FFRs) and surgical masks (SMs) against viral particles, as well as other health-relevant submicrometer particles. A FFR and SM were tested on a breathing manikin at four mean inspiratory flows (MIFs) (15, 30, 55, and 85 L/min) and five breathing frequencies (10, 15, 20, 25, and 30 breaths/min). Filter penetration (Pfilter) and total inward leakage (TIL) were determined for the tested respiratory protection devices against sodium chloride (NaCl) aerosol particles in the size range of 20 to 500 nm. "Faceseal leakage-to-filter" (FLTF) penetration ratios were calculated. Both MIF and breathing frequency showed significant effects (p < 0.05) on Pfilter and TIL. Increasing breathing frequency increased TIL for the N95 FFR whereas no clear trends were observed for the SM. Increasing MIF increased Pfilter and decreased TIL resulting in decreasing FLTF ratio. Most of FLTF ratios were >1, suggesting that the faceseal leakage was the primary particle penetration pathway at various breathing frequencies. Breathing frequency is another factor (besides MIF) that can significantly affect the performance of N95 FFRs, with higher breathing frequencies increasing TIL. No consistent trend of increase or decrease of TIL with either MIF or breathing frequency was observed for the tested SM. To potentially extend these findings beyond the manikin/breathing system used, future studies are needed to fully understand the mechanism causing the breathing frequency effect on the performance of respiratory protection devices on human subjects. PMID:24521067

  11. The effect of breath holding, hyperventilation, and exercise on nasal resistance.

    PubMed

    Hasegawa, M; Kern, E B

    1978-12-01

    A group of 51 patients was studied by a technique of active posterior rhinomanometry that assessed the influence of breath holding, hyperventilation, and exercise on nasal resistance. Breath hodling of 30 seconds or longer produced a decrease in nasal resistance in most of the subjects tested. Hyperventilation had variable effects on nasal resistance, and exercise consistently decreased nasal resistance. These observations are consistent with the proposed effect of chemoreceptor stimulation on nasal airway resistance.

  12. Measurement of low breath-alcohol concentrations: laboratory studies and field experience.

    PubMed

    Dubowski, K M; Essary, N A

    1999-10-01

    Recent federal rules and traffic law changes impose breath-alcohol thresholds of 0.02 and 0.04 g/210 L upon some classes of motor vehicle operators, such as juveniles and commercial vehicle operators. In federally regulated alcohol testing in the workplace, removal of covered workers from safety-sensitive duties, and other adverse actions, also occur at breath-alcohol concentrations (BrACs) of 0.02 and 0.04 g/210 L. We therefore studied performance of vapor-alcohol and breath-alcohol measurement at low alcohol concentrations in the laboratory and in the field, with current-generation evidential analyzers. We report here chiefly our field experience with evidential breath-alcohol testing of drinking drivers on paired breath samples using 62 Intoxilyzer 5000-D analyzers, for BrACs of 0-0.059 g/210 L. The data from 62 law enforcement breath-alcohol testing sites were collected and pooled, with BrACs recorded to three decimal places, and otherwise carried out under the standard Oklahoma evidential breath-alcohol testing protocol. For 2105 pooled simulator control tests at 0.06-0.13 g/210 L the mean +/- SD of the differences between target and result were -0.001 +/- 0.0035 g/210 L and 0.003 +/- 0.0023 g/210 L for signed and absolute differences, respectively (spans -0.016-0.010, 0.000-0.016). For 2078 paired duplicate breath-alcohol measurements with the Intoxilyzer 5000-D, the mean +/- SD difference (BrAC1-BrAC2) were 0.002 +/- 0.0026 (span 0-0.020 g/210 L). Variability of breath-alcohol measurements was related inversely to the alcohol concentration. Ninety-nine percent prediction limits for paired BrAC measurements correspond to a 0.020 g/210 L maximum absolute difference, meeting the NSC/CAOD recommendation that paired breath-alcohol analysis results within 0.02 g/210 L shall be deemed to be in acceptable agreement. We conclude that the field system for breath-alcohol analysis studied by us can and does perform reliably and accurately at low BrACs.

  13. Take a breath and take the turn: how breathing meets turns in spontaneous dialogue

    PubMed Central

    Rochet-Capellan, Amélie; Fuchs, Susanne

    2014-01-01

    Physiological rhythms are sensitive to social interactions and could contribute to defining social rhythms. Nevertheless, our knowledge of the implications of breathing in conversational turn exchanges remains limited. In this paper, we addressed the idea that breathing may contribute to timing and coordination between dialogue partners. The relationships between turns and breathing were analysed in unconstrained face-to-face conversations involving female speakers. No overall relationship between breathing and turn-taking rates was observed, as breathing rate was specific to the subjects' activity in dialogue (listening versus taking the turn versus holding the turn). A general inter-personal coordination of breathing over the whole conversation was not evident. However, specific coordinative patterns were observed in shorter time-windows when participants engaged in taking turns. The type of turn-taking had an effect on the respective coordination in breathing. Most of the smooth and interrupted turns were taken just after an inhalation, with specific profiles of alignment to partner breathing. Unsuccessful attempts to take the turn were initiated late in the exhalation phase and with no clear inter-personal coordination. Finally, breathing profiles at turn-taking were different than those at turn-holding. The results support the idea that breathing is actively involved in turn-taking and turn-holding. PMID:25385777

  14. Active breathing control (ABC): Determination and reduction of breathing-induced organ motion in the chest

    SciTech Connect

    Gagel, Bernd . E-mail: BGagel@UKAachen.de; Demirel, Cengiz M.P.; Kientopf, Aline; Pinkawa, Michael; Piroth, Marc; Stanzel, Sven; Breuer, Christian; Asadpour, Branka; Jansen, Thomas; Holy, Richard; Wildberger, Joachim E.; Eble, Michael J.

    2007-03-01

    Purpose: Extensive radiotherapy volumes for tumors of the chest are partly caused by interfractional organ motion. We evaluated the feasibility of respiratory observation tools using the active breathing control (ABC) system and the effect on breathing cycle regularity and reproducibility. Methods and Materials: Thirty-six patients with unresectable tumors of the chest were selected for evaluation of the ABC system. Computed tomography scans were performed at various respiratory phases starting at the same couch position without patient movement. Threshold levels were set at minimum and maximum volume during normal breathing cycles and at a volume defined as shallow breathing, reflecting the subjective maximal tolerable reduction of breath volume. To evaluate the extent of organ movement, 13 landmarks were considering using commercial software for image coregistration. In 4 patients, second examinations were performed during therapy. Results: Investigating the differences in a normal breathing cycle versus shallow breathing, a statistically significant reduction of respiratory motion in the upper, middle, and lower regions of the chest could be detected, representing potential movement reduction achieved through reduced breath volume. Evaluating interfraction reproducibility, the mean displacement ranged between 0.24 mm (chest wall/tracheal bifurcation) to 3.5 mm (diaphragm) for expiration and shallow breathing and 0.24 mm (chest wall) to 5.25 mm (diaphragm) for normal inspiration. Conclusions: By modifying regularity of the respiratory cycle through reduction of breath volume, a significant and reproducible reduction of chest and diaphragm motion is possible, enabling reduction of treatment planning margins.

  15. Take a breath and take the turn: how breathing meets turns in spontaneous dialogue.

    PubMed

    Rochet-Capellan, Amélie; Fuchs, Susanne

    2014-12-19

    Physiological rhythms are sensitive to social interactions and could contribute to defining social rhythms. Nevertheless, our knowledge of the implications of breathing in conversational turn exchanges remains limited. In this paper, we addressed the idea that breathing may contribute to timing and coordination between dialogue partners. The relationships between turns and breathing were analysed in unconstrained face-to-face conversations involving female speakers. No overall relationship between breathing and turn-taking rates was observed, as breathing rate was specific to the subjects' activity in dialogue (listening versus taking the turn versus holding the turn). A general inter-personal coordination of breathing over the whole conversation was not evident. However, specific coordinative patterns were observed in shorter time-windows when participants engaged in taking turns. The type of turn-taking had an effect on the respective coordination in breathing. Most of the smooth and interrupted turns were taken just after an inhalation, with specific profiles of alignment to partner breathing. Unsuccessful attempts to take the turn were initiated late in the exhalation phase and with no clear inter-personal coordination. Finally, breathing profiles at turn-taking were different than those at turn-holding. The results support the idea that breathing is actively involved in turn-taking and turn-holding.

  16. Delayed feedback applied to breathing in humans

    NASA Astrophysics Data System (ADS)

    Janson, N. B.; Pototsky, A.; Parkes, C.

    2013-10-01

    We studied the response of healthy volunteers to the delayed feedback generated from the breathing signals. Namely, in the freely-breathing volunteers the breathing signal was recorded, delayed by τ seconds and fed back to the same volunteer in real time in the form of a visual and auditory stimulus of low intensity, i.e. the stimulus was crucially non-intrusive. In each case volunteers were instructed to breathe in the way which was most comfortable for them, and no explanation about the kind of applied stimulus was provided to them. Each volunteer experienced 10 different delay times ranging between 10% and 100% of the average breathing period without external stimulus. It was observed that in a significant proportion of subjects (11 out of 24) breathing was slowed down in the presence of delayed feedback with moderate delay. Also, in 6 objects out of 24 the delayed feedback was able to induce transition from nearly periodic to irregular breathing. These observations are consistent with the phenomena observed in numerical simulation of the models of periodic and chaotic self-oscillations with delays, and also in experiments with simpler self-oscillating systems.

  17. An ultrasonic contactless sensor for breathing monitoring.

    PubMed

    Arlotto, Philippe; Grimaldi, Michel; Naeck, Roomila; Ginoux, Jean-Marc

    2014-01-01

    The monitoring of human breathing activity during a long period has multiple fundamental applications in medicine. In breathing sleep disorders such as apnea, the diagnosis is based on events during which the person stops breathing for several periods during sleep. In polysomnography, the standard for sleep disordered breathing analysis, chest movement and airflow are used to monitor the respiratory activity. However, this method has serious drawbacks. Indeed, as the subject should sleep overnight in a laboratory and because of sensors being in direct contact with him, artifacts modifying sleep quality are often observed. This work investigates an analysis of the viability of an ultrasonic device to quantify the breathing activity, without contact and without any perception by the subject. Based on a low power ultrasonic active source and transducer, the device measures the frequency shift produced by the velocity difference between the exhaled air flow and the ambient environment, i.e., the Doppler effect. After acquisition and digitization, a specific signal processing is applied to separate the effects of breath from those due to subject movements from the Doppler signal. The distance between the source and the sensor, about 50 cm, and the use of ultrasound frequency well above audible frequencies, 40 kHz, allow monitoring the breathing activity without any perception by the subject, and therefore without any modification of the sleep quality which is very important for sleep disorders diagnostic applications. This work is patented (patent pending 2013-7-31 number FR.13/57569). PMID:25140632

  18. Immediate effects of breath holding maneuvers onto composition of exhaled breath.

    PubMed

    Sukul, Pritam; Trefz, Phillip; Schubert, Jochen K; Miekisch, Wolfram

    2014-09-01

    Rapid concentration changes due to physiological or pathophysiological effects rather than appearance of unique disease biomarkers are important for clinical application of breath research. Simple maneuvers such as breath holding may significantly affect breath biomarker concentrations. In this study, exhaled volatile organic compound (VOC) concentrations were assessed in real time before and after different breath holding maneuvers. Continuous breath-resolved measurements (PTR-ToF-MS-8000) were performed in 31 healthy human subjects in a side-stream sampling mode. After 1 min of tidal breathing participants held their breath for 10, 20, 40, 60 s and as long as possible. Afterwards they continued to breathe normally for another minute. VOC profiles could be monitored in real time by assigning online PTR-ToF-MS data to alveolar or inspired phases of breath. Sudden and profound changes of exhaled VOC concentrations were recorded after different breath holding maneuvers. VOC concentrations returned to base line levels 10-20 s after breath holding. Breath holding induced concentration changes depended on physico-chemical properties of the substances. When substance concentrations were normalized onto end-tidal CO2 content, variation of acetone concentrations decreased, whereas variations of isoprene concentrations were not affected. As the effects of breathing patterns on exhaled substance concentrations depend on individual substance properties, sampling procedures have to be validated for each compound by means of appropriate real-time analysis. Normalization of exhaled concentrations onto exhaled CO2 is only valid for substances having similar physico-chemical properties as CO2.

  19. Breath Hydrogen as a Biomarker for Glucose Malabsorption after Roux-en-Y Gastric Bypass Surgery

    PubMed Central

    Andalib, Iman; Shah, Hiral; Bal, Bikram S.; Shope, Timothy R.; Finelli, Frederick C.; Koch, Timothy R.

    2015-01-01

    Objective. Abdominal symptoms are common after bariatric surgery, and these individuals commonly have upper gut bacterial overgrowth, a known cause of malabsorption. Breath hydrogen determination after oral glucose is a safe and inexpensive test for malabsorption. This study is designed to investigate breath hydrogen levels after oral glucose in symptomatic individuals who had undergone Roux-en-Y gastric bypass surgery. Methods. This is a retrospective study of individuals (n = 63; 60 females; 3 males; mean age 49 years) who had gastric bypass surgery and then glucose breath testing to evaluate abdominal symptoms. Results. Among 63 postoperative individuals, 51 (81%) had a late rise (≥45 minutes) in breath hydrogen or methane, supporting glucose malabsorption; 46 (90%) of these 51 subjects also had an early rise (≤30 minutes) in breath hydrogen or methane supporting upper gut bacterial overgrowth. Glucose malabsorption was more frequent in subjects with upper gut bacterial overgrowth compared to subjects with no evidence for bacterial overgrowth (P < 0.001). Conclusion. These data support the presence of intestinal glucose malabsorption associated with upper gut bacterial overgrowth in individuals with abdominal symptoms after gastric bypass surgery. Breath hydrogen testing after oral glucose should be considered to evaluate potential malabsorption in symptomatic, postoperative individuals. PMID:26538792

  20. Slow Breathing and Hypoxic Challenge: Cardiorespiratory Consequences and Their Central Neural Substrates

    PubMed Central

    Critchley, Hugo D.; Nicotra, Alessia; Chiesa, Patrizia A.; Nagai, Yoko; Gray, Marcus A.; Minati, Ludovico; Bernardi, Luciano

    2015-01-01

    Controlled slow breathing (at 6/min, a rate frequently adopted during yoga practice) can benefit cardiovascular function, including responses to hypoxia. We tested the neural substrates of cardiorespiratory control in humans during volitional controlled breathing and hypoxic challenge using functional magnetic resonance imaging (fMRI). Twenty healthy volunteers were scanned during paced (slow and normal rate) breathing and during spontaneous breathing of normoxic and hypoxic (13% inspired O2) air. Cardiovascular and respiratory measures were acquired concurrently, including beat-to-beat blood pressure from a subset of participants (N = 7). Slow breathing was associated with increased tidal ventilatory volume. Induced hypoxia raised heart rate and suppressed heart rate variability. Within the brain, slow breathing activated dorsal pons, periaqueductal grey matter, cerebellum, hypothalamus, thalamus and lateral and anterior insular cortices. Blocks of hypoxia activated mid pons, bilateral amygdalae, anterior insular and occipitotemporal cortices. Interaction between slow breathing and hypoxia was expressed in ventral striatal and frontal polar activity. Across conditions, within brainstem, dorsal medullary and pontine activity correlated with tidal volume and inversely with heart rate. Activity in rostroventral medulla correlated with beat-to-beat blood pressure and heart rate variability. Widespread insula and striatal activity tracked decreases in heart rate, while subregions of insular cortex correlated with momentary increases in tidal volume. Our findings define slow breathing effects on central and cardiovascular responses to hypoxic challenge. They highlight the recruitment of discrete brainstem nuclei to cardiorespiratory control, and the engagement of corticostriatal circuitry in support of physiological responses that accompany breathing regulation during hypoxic challenge. PMID:25973923

  1. Clinical comparison of Colgate Total Advanced Fresh vs a commercially available fluoride breath-freshening toothpaste in reducing breath odor overnight: a multiple-use study.

    PubMed

    Niles, Hollandra P; Hunter, Catherine M; Vazquez, Joe; Williams, Malcolm I; Cummins, Diane

    2003-09-01

    The objective of this randomized, crossover study was to compare the effectiveness of Colgate Total Advanced Fresh toothpaste to a commercially available breath-freshening dentifrice containing fluoride for its ability to reduce volatile sulfur compounds (VSC) responsible for breath odor overnight. The study followed a two-treatment, two-period crossover design. Subjects were given a test product, along with a soft-bristled toothbrush, and instructed to brush their teeth for 1 minute, twice daily (once in the morning and the evening) using the assigned dentifrice for 7 consecutive days. After their evening brushing on the seventh day, subjects reported to the testing facility without oral hygiene, eating, or drinking for the overnight evaluation. After a washout period, subjects repeated the same regimen, now using the other test product. The levels of breath VSC were evaluated instrumentally using a gas chromatograph equipped with a flame photometric detector.

  2. Applications of breath gas analysis in medicine

    NASA Astrophysics Data System (ADS)

    Amann, Anton; Poupart, Guy; Telser, Stefan; Ledochowski, Maximilian; Schmid, Alex; Mechtcheriakov, Sergei

    2004-12-01

    Volatile organic compounds (VOCs) in exhaled breath gas provide valuable information about the subjects' physiological and pathophysiological condition. Proton-transfer-reaction mass spectrometry (PTR-MS) allows rapid and online measurements of these substances. We present results of three studies illustrating the potential of breath gas analysis by PTR-MS in various contexts: long-time online monitoring of VOCs in sleeping subjects suggests that VOC profiles are related to sleep stages. Analysis of VOC concentrations in the breath of carbohydrate malabsorbers emphasizes the role played by bacteria in the gut. Finally, we demonstrate the large intra- and intersubject concentration variability of VOCs by considering one particular mass.

  3. Improved fireman's compressed air breathing system pressure vessel development program

    NASA Technical Reports Server (NTRS)

    King, H. A.; Morris, E. E.

    1973-01-01

    Prototype high pressure glass filament-wound, aluminum-lined pressurant vessels suitable for use in a fireman's compressed air breathing system were designed, fabricated, and acceptance tested in order to demonstrate the feasibility of producing such high performance, lightweight units. The 4000 psi tanks have a 60 standard cubic foot (SCF) air capacity, and have a 6.5 inch diamter, 19 inch length, 415 inch volume, weigh 13 pounds when empty, and contain 33 percent more air than the current 45 SCF (2250 psi) steel units. The current steel 60 SCF (3000 psi) tanks weigh approximately twice as much as the prototype when empty, and are 2 inches, or 10 percent shorter. The prototype units also have non-rusting aluminum interiors, which removes the hazard of corrosion, the need for internal coatings, and the possibility of rust particles clogging the breathing system.

  4. Transient Suppression of Dbx1 PreBötzinger Interneurons Disrupts Breathing in Adult Mice

    PubMed Central

    Vann, Nikolas C.; Pham, Francis D.; Hayes, John A.; Kottick, Andrew; Del Negro, Christopher A.

    2016-01-01

    Interneurons derived from Dbx1-expressing precursors located in the brainstem preBötzinger complex (preBötC) putatively form the core oscillator for inspiratory breathing movements. We tested this Dbx1 core hypothesis by expressing archaerhodopsin in Dbx1-derived interneurons and then transiently hyperpolarizing these neurons while measuring respiratory rhythm in vitro or breathing in vagus-intact adult mice. Transient illumination of the preBötC interrupted inspiratory rhythm in both slice preparations and sedated mice. In awake mice, light application reduced breathing frequency and prolonged the inspiratory duration. Support for the Dbx1 core hypothesis previously came from embryonic and perinatal mouse experiments, but these data suggest that Dbx1-derived preBötC interneurons are rhythmogenic in adult mice too. The neural origins of breathing behavior can be attributed to a localized and genetically well-defined interneuron population. PMID:27611210

  5. Welfare support-equipment for character input with head tilting and breathing

    NASA Astrophysics Data System (ADS)

    Nakazawa, Nobuaki; Yamada, Kou; Matsui, Toshikazu; Itoh, Isao

    2005-12-01

    This paper describes support-equipment of operating a personal computer for users who have an obstacle on the regions of upper limb. The user wears a head set device with an angle sensor, and holds a plastic pipe connected to a pressure sensor in his or her mouth. Tilting his or her head and breathing are used for mouse cursor operation and characters input. Considering user's body conditions, the voluntary angle range of head tilting and strength of breathing are memorized to the controller beforehand, and obtained information is reflected for operations without fatigue. The character display board is used to indicate the Japanese characters and input options such as Back Space or Enter. Tilting motions change the indicated character and breathing actions can select and input the illuminated functions on the character display board. In test trial, it is confirmed that Japanese characters including Kanji and Katakana can be input with head tilting and breathing, instead of a general keyboard.

  6. Application of thermal desorption to the biological monitoring of organic compounds in exhaled breath.

    PubMed

    Periago, J F; Prado, C; Ibarra, I; Tortosa, J

    1993-12-24

    We have developed a thermal desorption-gas chromatographic method for the analysis of organic compounds in exhaled breath air, to be used in the biological monitoring of environmental exposure. The exhaled breath sampler is based on the concentration of compounds present in alveolar air in a solid sorbent material. Isoflurane (1-chloro-2,2,2-trifluoroethyl-difluoromethyl-ether), an inhaled anaesthetic used widely in surgery, and styrene, used in boat construction and the manufacture of fibreglass-reinforced plastics, are partially eliminated from the body in exhaled breath, samples of which can therefore be used to monitor biological exposure to these two organic compounds. Recoveries were tested in controlled atmospheres of isoflurane or styrene, with Chromosorb 106 or Tenax, respectively, as the adsorbent. We also investigated the influence of relative humidity, an important factor in breath sampling, on adsorption.

  7. Transient Suppression of Dbx1 PreBötzinger Interneurons Disrupts Breathing in Adult Mice.

    PubMed

    Vann, Nikolas C; Pham, Francis D; Hayes, John A; Kottick, Andrew; Del Negro, Christopher A

    2016-01-01

    Interneurons derived from Dbx1-expressing precursors located in the brainstem preBötzinger complex (preBötC) putatively form the core oscillator for inspiratory breathing movements. We tested this Dbx1 core hypothesis by expressing archaerhodopsin in Dbx1-derived interneurons and then transiently hyperpolarizing these neurons while measuring respiratory rhythm in vitro or breathing in vagus-intact adult mice. Transient illumination of the preBötC interrupted inspiratory rhythm in both slice preparations and sedated mice. In awake mice, light application reduced breathing frequency and prolonged the inspiratory duration. Support for the Dbx1 core hypothesis previously came from embryonic and perinatal mouse experiments, but these data suggest that Dbx1-derived preBötC interneurons are rhythmogenic in adult mice too. The neural origins of breathing behavior can be attributed to a localized and genetically well-defined interneuron population. PMID:27611210

  8. Dead space in the breathing apparatus; interaction with ventilation.

    PubMed

    Warkander, D E; Lundgren, C E

    1995-09-01

    Dead space in breathing apparatus may cause increased ventilation and/or CO2 retention. Interactions between ventilation and dead space were tested in the breathing apparatus of three divers: a full face mask with an oro-nasal cup (AGA), a full face mask without an oro-nasal cup (EXO-26) but designed to minimize dead space, and one mouthpiece. Experiments were performed at three depths; 0, 30 and 45 m seawater (msw). The breathing gas was air except at 30 msw where it was 36 O2 in N2. Five certified SCUBA divers were exercised at three levels (0, 50 and 100 W). Ventilation and gas exchange were measured. The dead space in the AGA mask was not influenced by either depth or exercise (mean 0.201). The mean dead space of the EXO-26 was 0.341, but it increased with exercise (p < 0.001) and decreased with depth (p < 0.03). Since the dead space can vary with ventilation levels it is not sufficient to test breathing apparatus only at rest as is required by the US National Institute of Occupational Safety and Health. The mean ventilation with the EXO-26 was higher than with the AGA by 10% at 50 W (p < 0.05) and by 12% (p < 0.01) at 100 W. The same comparison for end-tidal CO2 showed mean increase by 0.30 kPa at the 100-W workload (P < 0.05); changes at other workloads were not statistically significant. Comparisons of the mean inspired PCO2 to the maximum values considered acceptable by various organizations showed that the mouthpiece was always acceptable, the AGA mask was marginally acceptable or better, while sometimes the EXO-26 was not acceptable.

  9. 42 CFR 84.72 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing tubes; minimum requirements. 84.72 Section 84.72 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL...-Contained Breathing Apparatus § 84.72 Breathing tubes; minimum requirements. Flexible breathing tubes...

  10. 42 CFR 84.72 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing tubes; minimum requirements. 84.72 Section 84.72 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL...-Contained Breathing Apparatus § 84.72 Breathing tubes; minimum requirements. Flexible breathing tubes...

  11. 42 CFR 84.72 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing tubes; minimum requirements. 84.72 Section 84.72 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL...-Contained Breathing Apparatus § 84.72 Breathing tubes; minimum requirements. Flexible breathing tubes...

  12. 42 CFR 84.72 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.72 Section 84.72 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL...-Contained Breathing Apparatus § 84.72 Breathing tubes; minimum requirements. Flexible breathing tubes...

  13. 42 CFR 84.72 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing tubes; minimum requirements. 84.72 Section 84.72 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL...-Contained Breathing Apparatus § 84.72 Breathing tubes; minimum requirements. Flexible breathing tubes...

  14. Portable breathing apparatus for coal mines

    NASA Technical Reports Server (NTRS)

    Vandolah, R. W.

    1972-01-01

    The state of the art in portable oxygen breathing equipment is reported. Considered are self-containing as well as chemically generating oxygen sources and their effectiveness and limitations in mine rescue operations.

  15. Coordination of Mastication, Swallowing and Breathing

    PubMed Central

    Matsuo, Koichiro; Palmer, Jeffrey B.

    2009-01-01

    Summary The pathways for air and food cross in the pharynx. In breathing, air may flow through either the nose or the mouth, it always flows through the pharynx. During swallowing, the pharynx changes from an airway to a food channel. The pharynx is isolated from the nasal cavity and lower airway by velopharyngeal and laryngeal closure during the pharyngeal swallow. During mastication, the food bolus accumulates in the pharynx prior to swallow initiation. The structures in the oral cavity, pharynx and larynx serve multiple functions in breathing, speaking, mastication and swallowing. Thus, the fine temporal coordination of feeding among breathing, mastication and swallowing is essential to provide proper food nutrition and to prevent pulmonary aspiration. This review paper will review the temporo-spatial coordination of the movements of oral, pharyngeal, and laryngeal structures during mastication and swallowing, and temporal coordination between breathing, mastication, and swallowing. PMID:20161022

  16. Does a Smaller Waist Mean Smelly Breath?

    MedlinePlus

    ... overnight on the surface of the tongue when saliva production is diminished." ; Tips to combat halitosis: ; 1. Drink ... after meals can help keep bad breath away. Saliva production increases during chewing and this can help neutralize ...

  17. Haemoptysis after breath-hold diving.

    PubMed

    Boussuges, A; Pinet, C; Thomas, P; Bergmann, E; Sainty, J M; Vervloet, D

    1999-03-01

    Pulmonary oedema has been described in swimmers and self-contained underwater breathing apparatus (Scuba) divers. This study reports three cases of haemoptysis secondary to alveolar haemorrhage in breath-hold divers. Contributory factors, such as haemodynamic modifications secondary to immersion, cold exposure, exercise and exposure to an increase in ambient pressure, could explain this type of accident. Furthermore, these divers had taken aspirin, which may have aggravated the bleeding.

  18. Extreme human breath-hold diving.

    PubMed

    Ferretti, G

    2001-04-01

    In this paper, the respiratory, circulatory and metabolic adjustments to human extreme breath-hold diving are reviewed. A survey of the literature reveals that in extreme divers, adaptive mechanisms take place that allow prolongation of apnoea beyond the limits attained by non-diving subjects, and preservation of oxygen stores during the dives. The occurrence of a diving response, including peripheral vasoconstriction, increased arterial blood pressure, bradycardia and lowered cardiac output, is strongly implicated. Some peripheral regions may be excluded from perfusion, with consequent reliance on anaerobic metabolism. In addition, extreme breath-hold divers show a blunted ventilatory response to carbon dioxide breathing, possibly as a consequence of frequent exposure to high carbon dioxide partial pressures during the dives. These mechanisms allow the attainment of particularly low alveolar oxygen (< 30 mmHg) and high alveolar carbon dioxide (> 50 mmHg) partial pressures at the end of maximal dry breath-holds, and reduce oxygen consumption during the dive at the expense of increased anaerobic glycolysis (rate of blood lactate accumulation > 0.04 mM.s-1). The current absolute world record for depth in breath-hold diving is 150 m. Its further improvement depends upon how far the equilibrium between starting oxygen stores, the overall rate of energy expenditure, the fraction of energy provided by anaerobic metabolism and the diving speed can be pushed, with consciousness upon emersion. The ultimate limit to breath-hold diving records may indeed be imposed by an energetic constraint. PMID:11374109

  19. Monitoring breath markers under controlled conditions.

    PubMed

    Righettoni, Marco; Ragnoni, Alessandro; Güntner, Andreas T; Loccioni, Claudio; Pratsinis, Sotiris E; Risby, Terence H

    2015-12-01

    Breath analysis has the potential to detect and monitor diseases as well as to reduce the corresponding medical costs while improving the quality of a patient's life. Herein, a portable prototype, consisting of a commercial breath sampler modified to work as a platform for solid-state gas sensors was developed. The sensor is placed close to the mouth (<10 cm) and minimizes the mouth-to-sensor path to avoid contamination and dilution of the target breath marker. Additionally with an appropriate cooling concept, even high sensor operating temperatures (e.g. 350 °C) could be used. Controlled sampling is crucial for accurate repeatable analysis of the human breath and these concerns have been addressed by this novel prototype. The device helps a subject control their exhaled flow rate which increases reproducibility of intra-subject breath samples. The operation of this flame-made selective chemo-resistive gas sensor is demonstrated by the detection of breath acetone. PMID:26469378

  20. Control of breathing in invertebrate model systems.

    PubMed

    Bell, Harold J; Syed, Naweed I

    2012-07-01

    The invertebrates have adopted a myriad of breathing strategies to facilitate the extraction of adequate quantities of oxygen from their surrounding environments. Their respiratory structures can take a wide variety of forms, including integumentary surfaces, lungs, gills, tracheal systems, and even parallel combinations of these same gas exchange structures. Like their vertebrate counterparts, the invertebrates have evolved elaborate control strategies to regulate their breathing activity. Our goal in this article is to present the reader with a description of what is known regarding the control of breathing in some of the specific invertebrate species that have been used as model systems to study different mechanistic aspects of the control of breathing. We will examine how several species have been used to study fundamental principles of respiratory rhythm generation, central and peripheral chemosensory modulation of breathing, and plasticity in the control of breathing. We will also present the reader with an overview of some of the behavioral and neuronal adaptability that has been extensively documented in these animals. By presenting explicit invertebrate species as model organisms, we will illustrate mechanistic principles that form the neuronal foundation of respiratory control, and moreover appear likely to be conserved across not only invertebrates, but vertebrate species as well. PMID:23723022